JP2022075040A - Magnetoresistive effect device, magnetic sensor, frequency converter, and filter - Google Patents

Abstract

To provide low power-consumption magnetoresistive device, magnetometer, frequency converter, filter, and oscillator.SOLUTION: A magnetoresistive device includes a magnetoresistive element and a first ferromagnetic layer, and the magnetoresistive element includes a second ferromagnetic layer, a third ferromagnetic layer, and a spacer layer sandwiched between the second ferromagnetic layer and the third ferromagnetic layer, and the high-frequency magnetic field is generated in the first ferromagnetic layer by applying a high-frequency voltage, and the high-frequency magnetic field is applied to the second ferromagnetic layer.SELECTED DRAWING: Figure 1

Description

The present invention relates to magnetoresistive devices, magnetic sensors, frequency converters and filters.

With the recent advanced information society, attention is focused on high-frequency components in the high-frequency band of GHz. Spintronics is being researched as a field that has the potential to be applied to new high-frequency components.

For example, Patent Document 1 describes a magnetic device using a high frequency current. The magnetic device described in Patent Document 1 operates by applying a high-frequency magnetic field generated by a high-frequency current to the magnetization free layer of the magnetoresistive sensor.

Japanese Unexamined Patent Publication No. 2017-153066

The magnetic device of Patent Document 1 requires a large high-frequency current in order to apply a large high-frequency magnetic field to increase the output, resulting in high power consumption.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a magnetoresistive device, a magnetic sensor, a frequency converter, and a filter having low power consumption.

The following means are provided to solve the above problems.

(1) The magnetic resistance effect device according to the first aspect includes a magnetic resistance effect element and a first ferromagnetic layer, and the magnetic resistance effect element includes a second ferromagnetic layer, a third ferromagnetic layer, and the like. A spacer layer sandwiched between the second ferromagnetic layer and the third ferromagnetic layer is provided, and the first ferromagnetic layer generates a high-frequency magnetic field by applying a high-frequency voltage, and the high-frequency field is generated. The magnetic field is applied to the second ferromagnetic layer.

(2) In the magnetoresistive effect device according to the above aspect, the first ferromagnetic layer may be on at least one side in the laminating direction of the magnetoresistive element.

(3) The magnetic resistance effect device according to the above embodiment may further include a metal layer and an insulating layer, the metal layer is sandwiched between the insulating layer and the first ferromagnetic layer, and the metal layer is formed. It may contain 5d transition metal elements.

(4) The magnetoresistive device according to the above embodiment further includes an insulating layer and an electrode, and the electrode is the magnetoresistive element with reference to the first ferromagnetic layer in the stacking direction of the magnetoresistive element. The insulating layer may be sandwiched between the electrode and the first ferromagnetic layer.

(5) The magnetic resistance effect device according to the above aspect further includes a non-magnetic layer and a fourth ferromagnetic layer, and the fourth ferromagnetic layer is between the magnetic resistance effect element and the first ferromagnetic layer. The non-magnetic layer may be sandwiched between the first ferromagnetic layer and the fourth ferromagnetic layer, and the fourth ferromagnetic layer may be thicker than the first ferromagnetic layer.

(6) In the magnetoresistive device according to the above aspect, the non-magnetic layer may contain an oxide containing magnesium.

(7) The magnetoresistive effect device according to the above aspect further includes a fifth ferromagnetic layer, and the fifth ferromagnetic layer is viewed from any direction in the plane orthogonal to the stacking direction of the magnetoresistive element. Therefore, it may be located at a position where it overlaps with the magnetoresistive element.

(8) In the magnetoresistive device according to the above aspect, a high frequency current may be applied to the magnetoresistive element.

(9) The magnetic resistance effect device according to the above embodiment further includes a first input port and a second input port, and the first input port is connected to the first ferromagnetic layer and inputs to the first input port. The high frequency voltage is applied to the first ferromagnetic layer by the first high frequency signal to be generated, the second input port is connected to the magnetoresistive effect element, and the second high frequency signal input to the second input port causes the second input port. The high frequency current may be applied to the magnetoresistive effect element.

(10) The magnetic resistance effect device according to the above embodiment further includes a first input port, and the first input port is connected to the first ferromagnetic layer and the magnetic resistance effect element to the first input port. The high frequency voltage is applied to the first ferromagnetic layer by the input first high frequency signal, and the high frequency current is applied to the magnetic resistance effect element by the first high frequency signal input to the first input port. May be good.

(11) In the magnetoresistive device according to the above aspect, the first input port, the first ferromagnetic layer, and the magnetoresistive element may be connected in series.

(12) The magnetoresistive effect device according to the above embodiment further includes a first signal line and a second signal line, and the first input port is connected to the first signal line and the second signal line. The first signal line may be connected to the first ferromagnetic layer, and the second signal line may be connected to the magnetoresistive effect element.

(13) The magnetoresistive device according to the above aspect further includes a yoke, in which the yoke sandwiches the first ferromagnetic layer when viewed from the plane direction of the first ferromagnetic layer, and a magnetic field generated in the gap is generated. It may be applied to the first ferromagnetic layer.

(14) The magnetic resistance effect device according to the above embodiment is a signal line connected to the magnetic resistance effect element and the first ferromagnetic layer, and an output port from which a signal output from the magnetic resistance effect element is output. And a DC application terminal to which a power source for applying a DC current or a DC voltage can be connected to the magnetic resistance effect element may be further provided.

(15) The magnetic resistance effect device according to the above aspect has a plurality of units each having the magnetic resistance effect element and the first ferromagnetic layer, and is connected to the magnetic resistance effect element of each of the plurality of units. , A plurality of signal lines connecting different units, an output port for outputting a signal output from any of the plurality of units, and one DC application terminal or a plurality of DC application terminals. The magnetic resistance effect element of each of the plurality of units is connected to one of the one DC application terminal or the plurality of DC application terminals, and the one DC application terminal or the plurality of DC application terminals is connected. A power source for applying a direct current or a direct current can be connected to the connected magnetic resistance effect element, and each of the plurality of signal lines has the magnetic resistance effect element of a different unit and the first ferromagnetic layer. The plurality of units may be connected in an annular shape by the plurality of signal lines.

(16) The magnetic sensor according to the second aspect has the magnetoresistive effect device according to the above aspect.

(17) The frequency converter according to the third aspect has the magnetoresistive effect device according to the above aspect.

(18) The filter according to the fourth aspect has the magnetoresistive effect device according to the above aspect.

The magnetoresistive effect device, magnetic sensor, frequency converter and filter according to the above aspect consume low power consumption.

It is a figure which shows typically the circuit structure of the magnetoresistive effect device which concerns on 1st Embodiment. It is a figure which shows typically the circuit structure of another example of the magnetoresistive effect device which concerns on 1st Embodiment. It is a schematic diagram for demonstrating an example of the operation as the magnetic sensor of the magnetoresistive effect device which concerns on 1st Embodiment. Phase difference between the magnitude of the external magnetic field applied to the magnetic resistance effect element and the phase of the first high frequency current and the phase of the resistance of the magnetic resistance effect element Δθ ₂ (Phase of the second high frequency current and the phase of the magnetic resistance effect element) It is a figure which showed the relationship with the phase difference Δθ ₁ ) with the phase of a resistor. It is a schematic diagram for demonstrating the operation of the magnetic sensor which detects the direction of an external magnetic field. It is a schematic diagram for demonstrating the operation of the magnetic sensor which detects the direction of an external magnetic field. It is a figure which shows the circuit structure of the magnetoresistive effect device which concerns on the 1st modification. It is an enlarged view of the vicinity of the magnetoresistive effect element of the magnetoresistive effect device which concerns on the 1st modification. It is an enlarged view of the vicinity of the magnetoresistive effect element of the magnetoresistive effect device which concerns on the 2nd modification. It is an enlarged view of the vicinity of the magnetoresistive effect element of the magnetoresistive effect device which concerns on the 3rd modification. It is an enlarged view of the vicinity of the magnetoresistive effect element of another example of the magnetoresistive effect device which concerns on the 3rd modification. It is an enlarged view of the vicinity of the magnetoresistive effect element of the magnetoresistive effect device which concerns on the 4th modification. It is a figure which looked at the vicinity of the magnetoresistive element of the magnetoresistive device which concerns on 4th modification from the stacking direction of a magnetoresistive element. Another example of the magnetoresistive effect device according to the fourth modification is a plan view from the stacking direction of the magnetoresistive effect elements. It is an enlarged view of the vicinity of the magnetoresistive effect element of another example of the magnetoresistive effect device which concerns on the 4th modification. It is a figure which shows the circuit structure of the magnetoresistive effect device which concerns on 5th modification. It is a figure which looked at the vicinity of the magnetoresistive element of the magnetoresistive device which concerns on 5th modification from the stacking direction of a magnetoresistive element. It is a figure which looked at the vicinity of the magnetoresistive element of another example of the magnetoresistive device which concerns on 5th modification from the stacking direction of the magnetoresistive element. It is a figure which shows the circuit structure of the magnetoresistive effect device which concerns on the 6th modification. It is a figure which shows typically the circuit structure of the magnetoresistive effect device which concerns on 2nd Embodiment. It is a figure which shows typically the circuit structure of the magnetoresistive effect device which concerns on 3rd Embodiment. It is a figure which shows typically the circuit structure of another example of the magnetoresistive effect device which concerns on 3rd Embodiment. It is a figure which shows the circuit structure of the magnetoresistive effect device which concerns on 7th modification. It is a figure which shows the circuit structure of another example of the magnetoresistive effect device which concerns on 7th modification. It is a figure which shows the circuit structure of the magnetoresistive effect device which concerns on 8th modification. It is a figure which shows typically the circuit structure of the magnetoresistive effect device which concerns on 4th Embodiment. It is a figure which shows typically the circuit structure of the magnetoresistive effect device which concerns on the 9th modification. It is a figure which shows typically the circuit structure of the magnetoresistive effect device which concerns on the 10th modification. It is a figure which shows schematically the circuit structure of another example of the magnetoresistive effect device which concerns on 11th modification.

Hereinafter, the magnetoresistive effect device and the like will be described in detail with reference to the drawings as appropriate. In the drawings used in the following description, the featured portion may be enlarged for convenience in order to make the feature easy to understand, and the dimensional ratio of each component may be different from the actual one. The materials, dimensions, and the like exemplified in the following description are examples, and the present invention is not limited thereto, and can be appropriately modified and carried out within the range in which the effects of the present invention are exhibited.

"First embodiment"
(Magnetic resistance effect device)
FIG. 1 is a diagram showing a circuit configuration of the magnetoresistive device 100 according to the first embodiment. The magnetoresistive effect device 100 includes a magnetoresistive effect element 10 and a first ferromagnetic layer 20. The magnetoresistive device 100 shown in FIG. 1 also includes a first input port p1, a second input port p2, an output port p3, a reference potential terminal pr1, pr2, a capacitor C, a filter F, and signal lines L1 to L5. Have. The arrow of the high frequency current _IR shown in FIG. 1 indicates the positive direction of the current. The same applies to other drawings described later.

In FIG. 1, the signal line L1 connects the first input port p1 and the first ferromagnetic layer 20. As used herein, "connecting" is not limited to the case where two objects are directly connected. For example, if a voltage or current caused by a signal flowing through the object A is applied to the object B, it can be said that the object A and the object B are connected. The first input port p1 is connected to the first ferromagnetic layer 20 via the signal line L1. The signal line L2 connects the first ferromagnetic layer 20 and the reference potential terminal pr1. The signal line L3 connects the second input port p2 and the magnetoresistive effect element 10. The second input port p2 is connected to the magnetoresistive effect element 10 via the signal line L3. The signal line L4 connects the signal line L3 and the output port p3. The signal line L5 connects the magnetoresistive effect element 10 and the reference potential terminal pr2. The capacitor C is on the second input port p2 side from the branch point with the signal line L4 on the signal line L3. The filter F is on the signal line L4.

<Magnetic resistance effect element>
The magnetoresistive element 10 includes a second ferromagnetic layer 1, a third ferromagnetic layer 2, and a spacer layer 3. The spacer layer 3 is located between the second ferromagnetic layer 1 and the third ferromagnetic layer 2. Hereinafter, the stacking direction of the second ferromagnetic layer 1, the third ferromagnetic layer 2, and the spacer layer 3 may be simply referred to as a “stacking direction”.

The second ferromagnetic layer 1 is, for example, a magnetization free layer (first magnetization free layer). The third ferromagnetic layer 2 is, for example, a fixed magnetization layer or a free magnetization layer (second free magnetization layer). When the third ferromagnetic layer 2 functions as a magnetization fixed layer, the coercive force of the third ferromagnetic layer 2 is larger than, for example, the coercive force of the second ferromagnetic layer 1. The magnetization free layer is a layer made of a magnetic material whose magnetization direction changes when a predetermined external force is applied, and the magnetization fixed layer has a magnetization direction different from that of the magnetization free layer when a predetermined external force is applied. Is a layer made of a magnetic material that does not easily change. The predetermined external force is, for example, an external force applied to the magnetization by an external magnetic field.

The magnetic resistance effect element 10 causes a resistance value in the stacking direction (current flows in the stacking direction) according to a change in the relative angle between the magnetization direction of the second ferromagnetic layer 1 and the magnetization direction of the third ferromagnetic layer 2. (Resistance value when this is done) changes. The third ferromagnetic layer 2 may be a fixed magnetization layer or a free magnetization layer as long as the relative angle of the magnetization direction of the second ferromagnetic layer 1 to the magnetization direction of the third ferromagnetic layer 2 changes.

The second ferromagnetic layer 1 and the third ferromagnetic layer 2 include a ferromagnet. For example, the second ferromagnetic layer 1 and the third ferromagnetic layer 2 can use a metal such as Cr, Mn, Co, Fe, or Ni, or an alloy containing one or more of these metal elements as a constituent material. Further, an alloy of the above-mentioned metal element and at least one element selected from B, C and N may be used for the second ferromagnetic layer 1 and the third ferromagnetic layer 2. For example, the second ferromagnetic layer 1 and the third ferromagnetic layer 2 may have a CoFeB alloy as a main component when functioning as a magnetization free layer. The second ferromagnetic layer 1 and the third ferromagnetic layer 2 may each be composed of a plurality of layers.

Further, the second ferromagnetic layer 1 and the third ferromagnetic layer 2 may be an intermetallic compound (Whisler alloy) represented by a chemical composition of XYZ or _X2YZ . X is a transition metal element or a noble metal element of the group Co, Fe, Ni or Cu on the periodic table. Y is a transition metal element of the group Mn, V, Cr or Ti or an element represented by X. Z is a typical element of groups III to V. For example, Co ₂ FeSi, Co ₂ MnSi, Co ₂ Mn _1-a Fe _a Al _b Si _1-b (0 ≦ a ≦ 1, 0 ≦ b ≦ 1) and the like are known as Whistler alloys.

The second ferromagnetic layer 1 and the third ferromagnetic layer 2 may be an in-plane magnetizing film having an easy-to-magnetize axis in the in-plane direction of the film or a vertical magnetization film having an easy-to-magnetize axis in the direction perpendicular to the film surface.

In order to use the ferromagnetic layer as an in-plane magnetization film, the layer in contact with the ferromagnetic layer is made of a material that does not easily exhibit interfacial magnetic anisotropy. Examples of the material that does not easily develop interfacial magnetic anisotropy include Ru and Cu. On the other hand, in order to make the ferromagnetic layer a vertical magnetization film, the layer in contact with the ferromagnetic layer is made of a material that easily develops interfacial magnetic anisotropy. Examples of the material that easily develops interfacial magnetic anisotropy include MgO, W, Ta, Mo and the like. The layer of these materials in contact with the ferromagnetic layer may be provided on one side of the ferromagnetic layer in the direct direction of the film surface. Further, the second ferromagnetic layer 1 or the third ferromagnetic layer 2 may be formed by a laminated film in which a layer of these materials in contact with the ferromagnetic layer is sandwiched between a plurality of ferromagnetic layers.

When the third ferromagnetic layer 2 functions as a fixed magnetization layer, an antiferromagnetic layer may be added so as to be in contact with the third ferromagnetic layer 2. Further, the magnetization of the third ferromagnetic layer 2 may be fixed by utilizing the magnetic anisotropy caused by the crystal structure, shape, and the like. For the antiferromagnetic layer, FeO, CoO, NiO, CuFeS ₂ , IrMn, FeMn, PtMn, Cr, Mn or the like can be used.

The spacer layer 3 is a non-magnetic layer arranged between the second ferromagnetic layer 1 and the third ferromagnetic layer 2. The spacer layer 3 is composed of a layer made of a conductor, an insulator or a semiconductor, or a layer containing an energizing point made of a conductor in the insulator.

For example, when the spacer layer 3 is made of an insulator, the magnetoresistive effect element 10 becomes a tunnel magnetoresistive (TMR: Tunnel Magnetoresistion) effect element, and when the spacer layer 3 is made of metal, a giant magnetoresistive (GMR: Giant Magnetoresisment). It becomes an effect element.

When the spacer layer 3 is made of an insulating material, a material such as aluminum oxide, magnesium oxide, titanium oxide or silicon oxide can be used. A high rate of change in magnetic resistance can be obtained by adjusting the film thickness of the spacer layer 3 so that a high TMR effect is exhibited between the second ferromagnetic layer 1 and the third ferromagnetic layer 2. In order to efficiently utilize the TMR effect, the film thickness of the spacer layer 3 may be about 0.5 to 10.0 nm.

When the spacer layer 3 is made of a non-magnetic conductive material, a conductive material such as Cu, Ag, Au or Ru can be used. In order to efficiently utilize the GMR effect, the film thickness of the spacer layer 3 may be about 0.5 to 3.0 nm.

When the spacer layer 3 is made of a non-magnetic semiconductor material, a material such as zinc oxide, indium oxide, tin oxide, germanium oxide, gallium oxide or ITO can be used. In this case, the film thickness of the spacer layer 3 may be about 1.0 to 4.0 nm.

When a layer including a current-carrying point composed of a conductor in a non-magnetic insulator is applied as the spacer layer 3, CoFe, CoFeB, CoFeSi, CoMnGe, and CoMnSi are contained in the non-magnetic insulator composed of aluminum oxide or magnesium oxide. , ComnAl, Fe, Co, Au, Cu, Al or Mg, it is preferable to have a structure including a current-carrying point composed of a conductor. In this case, the film thickness of the spacer layer 3 may be about 0.5 to 2.0 nm.

In order to increase the electrical conductivity to the magnetoresistive element 10, electrodes may be provided on both sides of the magnetoresistive element 10 in the stacking direction. By providing electrodes on both ends of the magnetoresistive element 10 in the stacking direction, the contact between each line and the magnetoresistive element 10 becomes a surface, and a signal can be obtained at any position in the in-plane direction of the magnetoresistive element 10. The flow of (current) is along the stacking direction.

The magnetoresistive sensor 10 may have another layer. For example, the magnetoresistive element 10 may have a seed layer or a buffer layer on the surface of the third ferromagnetic layer 2 opposite to the second ferromagnetic layer 1. Further, the magnetoresistive element 10 may have a cap layer on the surface of the second ferromagnetic layer 1 opposite to the third ferromagnetic layer 2. Examples of the cap layer, the seed layer or the buffer layer include MgO, W, Mo, Ru, Ta, Cu, Cr or a laminated film thereof. The film thickness of each of these layers may be about 2 to 10 nm.

<First ferromagnetic layer>
The first ferromagnetic layer 20 generates a high frequency magnetic field by applying a high frequency voltage. For example, in FIG. 1, when the first high frequency signal S1 is input to the _first input port p1, the potential of the first input port p1 with respect to the reference potential fluctuates, and the high frequency voltage _VR is applied to the first ferromagnetic layer 20. Applied. The magnetic anisotropy of the first ferromagnetic layer 20 is changed by an electric field due to the effect of voltage-controlled magnetic anisotropy (VCMA). Therefore, the magnetic anisotropy of the first ferromagnetic layer 20 changes periodically by the high frequency voltage _VR , and the magnetization of the first ferromagnetic layer 20 undergoes a aging motion. The precession of the magnetization of the first ferromagnetic layer 20 produces a high frequency magnetic field _HR . The first ferromagnetic layer 20 generates a high frequency magnetic field _HR by the high frequency voltage _VR . The high-frequency magnetic field _HR generated in the first ferromagnetic layer 20 is applied to the second ferromagnetic layer 1 of the magnetoresistive sensor 10. The first ferromagnetic layer 20 may be referred to as a magnetic field application layer in which a high frequency magnetic field _HR is applied to the second ferromagnetic layer 1.

The first ferromagnetic layer 20 is on at least one side of the magnetoresistive element 10 in the stacking direction. The first ferromagnetic layer 20 is, for example, on the second ferromagnetic layer 1 side of the magnetoresistive element 10. When the distance between the first ferromagnetic layer 20 and the second ferromagnetic layer 1 is short, the high-frequency magnetic field _HR generated in the first ferromagnetic layer 20 can be efficiently applied to the second ferromagnetic layer 1. In FIG. 1, the first ferromagnetic layer 20 is separated from the magnetoresistive element 10. As will be described later, the first ferromagnetic layer 20 and the magnetoresistive element 10 may be in contact with each other.

The first ferromagnetic layer 20 is separated from the magnetoresistive element 10 via an insulator, for example. The insulator may be an insulator or a space. The first ferromagnetic layer 20 is arranged at a position where a high frequency magnetic field _HR generated by applying a high frequency voltage can be applied to the second ferromagnetic layer 1.

The first ferromagnetic layer 20 contains, for example, a soft magnetic material. The first ferromagnetic layer 20 is, for example, a ferromagnet having an insulating property. The first ferromagnetic layer 20 is, for example, a ceramic such as ferrite. The first ferromagnetic layer 20 is, for example, a rare earth iron garnet (RIG). Yttrium iron garnet (YIG) is an example of rare earth iron garnet (RIG). The first ferromagnetic layer 20 may be a metal such as permalloy. The first ferromagnetic layer 20 may be, for example, a metal such as Cr, Mn, Co, Fe, or Ni, or an alloy containing one or more of these metal elements. The first ferromagnetic layer 20 may use an alloy of the above-mentioned metal element and at least one element selected from B, C and N. For example, the first ferromagnetic layer 20 may have a CoFeB alloy as a main component.

FIG. 2 is a diagram showing a circuit configuration of another example of the magnetoresistive device according to the first embodiment. FIG. 2 is an example of the case where the first ferromagnetic layer 20 has conductivity. The magnetoresistive device 101 shown in FIG. 2 has an insulating layer 30 and an electrode 40.

When the first ferromagnetic layer 20 has conductivity, for example, an insulating layer 30 is provided between the signal line L1 and the signal line L2. The insulating layer 30 is sandwiched between, for example, the electrode 40 and the first ferromagnetic layer 20. The electrode 40 is, for example, on the opposite side of the magnetoresistive element 10 with respect to the first ferromagnetic layer 20 in the stacking direction. When the electrode 40 is on the opposite side of the magnetic resistance effect element 10 with respect to the first ferromagnetic layer 20, the distance between the first ferromagnetic layer 20 and the second ferromagnetic layer 1 becomes closer, and the first ferromagnetic layer 20 becomes closer. The generated high-frequency magnetic field _HR can be efficiently applied to the second ferromagnetic layer 1.

<1st input port>
The first input port p1 is the first input terminal of the magnetoresistive device 100. For example, an AC signal source, an antenna, or the like is connected to the first input port p1. If the antenna is integrated with the magnetoresistive device as part of the magnetoresistive device, the antenna will be the first input port.

The first high frequency signal S1 is input to the _first input port p1. The first high frequency signal S ₁ produces a high frequency voltage _VR in the first ferromagnetic layer 20. The frequency of the first high frequency signal S ₁ is, for example, a signal having a frequency of 100 MHz or more. The frequency of the high frequency voltage _VR coincides with the frequency of the _first high frequency signal S1.

<Second input port>
The second input port p2 is the second input terminal of the magnetoresistive device 100. For example, an AC signal source, an antenna, or the like is connected to the second input port p2. If the antenna is integrated with the magnetoresistive device as part of the magnetoresistive device, the antenna becomes the second input port.

The second high frequency signal S2 is input to the _second input port p2. The second high-frequency signal _{S 2} input to the second input port is applied to the magnetoresistive element 10 as a high-frequency current IR via the signal line L3. The high frequency current _IR flows through the magnetoresistive element 10. The amplitude of the vibration of the magnetization of the second ferromagnetic layer 1 due to the high-frequency magnetic field _HR applied to the second ferromagnetic layer 1 is the second ferromagnetic layer due to the spin transfer torque generated by the high-frequency current flowing through the magnetic resistance effect element 10. It is larger than the amplitude of the vibration of the magnetization of 1. The frequency of the second high frequency signal S ₂ is, for example, a signal having a frequency of 100 MHz or more. The frequency of the high frequency current IR coincides with the frequency of the second high frequency signal _{S 2} .

<Output port>
The output port p3 is an output terminal of the magnetoresistive device 100. To the output port p3, for example, a signal processing device for processing the output signal, for example, a voltmeter for monitoring the voltage, an ammeter for monitoring the current, an antenna for outputting a high frequency signal to the outside, and the like are connected. The output port p3 is connected to the magnetoresistive effect element 10 via the signal lines L3 and L4 and the filter F. A signal caused by the output from the magnetoresistive sensor 10 is output from the output port p3.

<Reference potential terminal>
The reference potential terminals pr1 and pr2 are connected to the reference potential and determine the reference potential of the magnetoresistive device 100. The reference potential terminal pr1 is connected to the signal line L2. The reference potential terminal pr2 is connected to the signal line L5. The reference potential in FIG. 1 is ground G. The ground G may be provided outside the magnetoresistive device 100. The reference potential may be other than ground G.

<Capacitor>
The capacitor C passes the high frequency component of the signal and cuts the invariant component of the signal. The capacitor C is arranged in a portion where the flow of the DC signal is to be suppressed. The capacitor C in FIG. 1 is on the signal line L3. The capacitor C is on the second input port p2 side from the branch point of the signal line L3 with the signal line L4. A known capacitor C can be used.

<Filter F>
The filter F is located between the magnetoresistive sensor 10 and the output port p3. The filter F is, for example, on the signal line L4. The filter F cuts a signal of a specific frequency and passes only a signal of a specific frequency. For example, when the magnetic resistance effect device 100 outputs a signal including a DC signal component (DC voltage or DC current) caused by the output from the magnetic resistance effect element 10, the filter F cuts the high frequency signal component of the signal. Pass the DC signal component. The filter F is, for example, an inductor, a high-pass filter, a low-pass filter, and a band elimination filter. The inductor may be, for example, a chip inductor, an inductor with a pattern line, a resistance element having an inductor component, or the like. The inductance of the inductor may be, for example, 10 nH or more. If the voltmeter or ammeter connected to the output port p3 has a filter function, the filter F may be omitted.

<Signal line>
The signal lines L1 to L5 connect between the components of the magnetoresistive device 100 and the terminals or between the components. The shape of the signal lines L1 to L5 may be defined as a microstrip line (MSL) type or a coplanar waveguide (CPW) type. When designing a microstrip line (MSL) type or coplanar waveguide (CPW) type, design the line width and ground-to-ground distance so that the characteristic impedance of the signal lines L1 to L5 and the impedance of the circuit system are equal. May be. By designing in this way, the transmission loss of the signal lines L1 to L5 can be suppressed.

(Use and operation of magnetoresistive device)
The magnetoresistive effect devices 100 and 101 can be used, for example, as a magnetic sensor and a frequency converter.

<Magnetic sensor>
The applications and operations of the magnetoresistive devices 100 and 101 as magnetic sensors will be described. Hereinafter, the signal output from the output port p3 will be described with reference to an example of a DC voltage. The magnetic sensor can detect, for example, a change in the magnitude of the applied external magnetic field, a value of the external magnetic field, and a direction of the external magnetic field.

"Sensing changes in the magnitude of the external magnetic field"
3A and 3B are schematic views for explaining the operation of the magnetoresistive device 100 as a magnetic sensor. 3A and 3B show a high-frequency voltage VR applied to the first ferromagnetic layer 20, a resistance _R10 of the magnetoresistive sensor ₁₀ , and a high-frequency current applied to the magnetoresistive sensor 10, respectively. The time change of the DC voltage _VDC output from the IR and the output port _p3 is shown. FIG. 3A shows a state in which an external magnetic field having a magnitude of that is applied to the magnetoresistive effect element 10 (state before the change), and FIG. 3B shows a state in which the magnetoresistive effect element 10 is applied. This is the state after the external magnetic field has changed (increased). The external magnetic field is a magnetic field applied to the magnetoresistive element 10 from other than each configuration of the magnetoresistive device 100.

First, the state before the change of the external magnetic field applied to the magnetoresistive effect element 10 will be described. When the first high frequency signal S1 is input to the _first input port p1 from the AC signal source connected to the first input port p1, the high frequency voltage _VR is applied to the first ferromagnetic layer 20. By applying the high frequency voltage _VR to the first ferromagnetic layer 20, a high frequency magnetic field _HR is generated. The high frequency magnetic field _HR is applied to the second ferromagnetic layer 1 of the magnetoresistive sensor 10.

The magnetization of the second ferromagnetic layer 1 vibrates under the high frequency magnetic field _HR . In the state before the external magnetic field applied to the magnetic resistance effect element 10 changes, as an example, the ferromagnetic resonance frequency of the second ferromagnetic layer 1 is the high frequency magnetic field _HR applied to the second ferromagnetic layer 1. Less than the frequency. The resistance R ₁₀ of the magnetoresistive element 10 changes (vibrates) due to the vibration of the magnetization of the second ferromagnetic layer 1. The phase of the high frequency voltage VR and the phase of the resistance _{R 10} of the magnetoresistive effect element 10 may be different, but FIG. 3A shows an example of matching. The phase difference between the high-frequency voltage VR and the resistance _{R 10} of the magnetoresistive sensor 10 is the position of each component, the direction of the high-frequency magnetic field _HR applied to the second ferromagnetic layer 1, and the third ferromagnetic layer. It can be changed by the relative angle with the direction of magnetization of 2.

When the second high frequency signal S2 is input to the _second input port p2 from the AC signal source connected to the second input port p2, the high frequency current _IR flows through the magnetoresistive effect element 10. The phase of the high frequency current _IR and the phase of the high frequency voltage _VR may be different, but FIGS. 3 (a) and 3 (b) show examples of matching. That is, in the example shown in FIG. 3A, the phase of the high frequency current IR and the phase of the resistance _{R 10} of the magnetoresistive element 10 coincide with each other.

When the _first high frequency signal S1 and the _second high frequency signal S2 are input to the magnetoresistive effect device 100, the DC voltage _VDC caused by the output from the magnetoresistive effect element 10 is output from the output port p3.

The DC voltage _VDC is the resistance _{R 10} of the magnetic resistance effect element 10 and the current (high frequency current IR) flowing through the magnetic resistance effect element 10 that changes when the high frequency magnetic field _HR is applied to the first ferromagnetic layer 20. It is a DC component of the voltage V (output voltage from the magnetic resistance effect element 10) which is the product of.
IR = A · sin ( _2πft ),
R ₁₀ = B · sin (2πft + Δθ ₁ ) + R ₀
Then
V = IR x _{R 10} = (A · B / 2) · {cos (Δθ ₁ ) -cos (4πft + Δθ ₁ )} + A · R ₀ · sin (2πft)
Is.

The DC voltage V _DC is a DC component of the voltage V, and is (A · B / 2) · cos (Δθ ₁ ). A is the amplitude of the high-frequency current IR, B is the amplitude of the resistance _{R 10} of the magnetic resistance effect element 10, and R ₀ is the magnetization of the second ferromagnetic layer 1 of the resistance of the magnetic resistance effect element 10. The resistance component does not depend on the relative angle of the magnetization of the third ferromagnetic layer 2, f is the frequency, t is the time, Δθ ₁ is the phase of the high frequency current IR and the resistance _{R 10} of the magnetic resistance effect element 10. Is the phase difference from the phase of. Hereinafter, it may be simply referred to as “phase difference Δθ ₁ ”. Further, the phase difference between the phase of the high frequency voltage VR and the phase of the resistance _{R 10} of the magnetoresistive effect element 10 is Δθ ₂ (hereinafter, may be simply referred to as “phase difference Δθ ₂ ”).

In the case shown in FIG. 3A, Δθ ₁ = 0 (0 °), and the DC voltage _VDC output from the output port p3 is A / B / 2.

Next, the state after the external magnetic field applied to the magnetoresistive effect element 10 has changed (increased) will be described. When the external magnetic field applied to the magnetoresistive element 10 changes, the state of vibration (age difference motion) of the magnetization of the second ferromagnetic layer 1 changes. As a result, the phase of the resistance R ₁₀ of the magnetoresistive effect element 10 changes. Since the phase of the high frequency current IR does not change, a phase difference Δθ ₁ occurs between the phase of the high frequency current _IR and the phase of the resistor _{R 10} of the magnetoresistive sensor 10.

So far, when the ferromagnetic resonance frequency of the second ferromagnetic layer 1 is sufficiently smaller than the frequency of the high frequency magnetic field _HR (frequency of the high frequency voltage _VR ), the phase of the high frequency voltage VR and the resistance _R of the magnetic resistance effect element 10 The example has been described in which the phases of ₁₀ are in agreement (Δθ ₂ = 0 (0 °)). In the case of this example, when the ferromagnetic resonance frequency of the second ferromagnetic layer 1 is sufficiently larger than the frequency of the high frequency magnetic field _HR , the phase difference Δθ ₂ becomes π (180 °). When the external magnetic field applied to the magnetic resistance effect element 10 becomes large and the effective magnetic field inside the second ferromagnetic layer 1 becomes large, the ferromagnetic resonance frequency of the second ferromagnetic layer 1 becomes large. Therefore, in the case of this example, as shown in FIG. 4, the phase difference Δθ ₂ and the phase difference Δθ ₁ change according to the change in the magnitude of the external magnetic field applied to the magnetoresistive effect element 10.

As described above, the DC voltage _VDC is (A · B / 2) · cos (Δθ ₁ ), and when the phase difference Δθ ₁ changes, the output value of the DC voltage _VDC changes. That is, the magnetoresistive device 100 can detect that the magnitude of the external magnetic field has changed based on the DC voltage _VDC output from the output port p3, and functions as a magnetic sensor. As an example, it is possible to detect a change from a state in which the phase difference Δθ ₁ is 0 (0 °) to a state in which the phase difference Δθ ₁ is π (180 °). The value of the phase difference Δθ ₁ before and after the change in the magnitude of the external magnetic field is not limited to 0 (0 °) or π (180 °), but can be any value between 0 and π (0 ° to 180 °). Can be used. In the magnetic resistance effect device 100, since the magnetization of the second ferromagnetic layer 1 is vibrated by the high frequency magnetic field _HR caused by the high frequency voltage _VR , the amplitude of the magnetization of the magnetization of the second ferromagnetic layer 1 can be increased. When the amplitude of the magnetization vibration of the second ferromagnetic layer 1 becomes large, the amount of change (amplitude) of the resistance R ₁₀ of the magnetoresistive effect element 10 becomes large, and a large DC voltage _VDC can be output from the output port p3. Further, in the magnetoresistive device 100, since it is not necessary to pass a large high-frequency current in order to apply a large high-frequency magnetic field to the second ferromagnetic layer 1, the power consumption required to generate the high-frequency magnetic field _HR is suppressed. be able to.

"Sensing of external magnetic field values"
The magnetoresistive device 100 can also obtain the value (specific magnitude) of the external magnetic field. As shown in FIG. 4, the phase difference Δθ ₂ and the phase difference Δθ ₁ are, for example, 0 (0 °) (Δθ ₁ , Δθ ₂ = 0) when the magnitude of the external magnetic field is less than the first value. When the magnitude of the external magnetic field is larger than the second value (second value> first value), it is π (180 °) (Δθ ₁ , Δθ ₂ = π). When the magnitude of the external magnetic field is equal to or greater than the first value and equal to or less than the second value, the magnitude of the external magnetic field changes sharply. In the region where the magnitude of the external magnetic field is equal to or greater than the first value and equal to or less than the second value, the magnitude of the external magnetic field and the phase differences Δθ ₁ and Δθ ₂ have a one-to-one relationship. That is, if the phase differences Δθ ₁ and Δθ ₂ are known, the specific magnitude of the external magnetic field can be detected. The phase difference Δθ ₁ can be derived from the value of the DC voltage _VDC . It is also possible to obtain the amount of change in the magnitude of the external magnetic field from the amount of change in the value of the DC voltage _VDC . Further, the changes in the phase differences Δθ ₁ and Δθ ₂ with respect to the change in the external magnetic field are steep, and the magnetic sensor can detect the change in the magnitude of the external magnetic field with high sensitivity.

"Sensing of the direction of the external magnetic field"
Next, a method of detecting the direction of the external magnetic field will be described. 5 and 6 are diagrams showing an example of the magnetization state of the first ferromagnetic layer 20, the second ferromagnetic layer 1 and the third ferromagnetic layer 2 when _detecting the direction of the external magnetic field He. .. In FIGS. 5 and 6, the magnetization of the ferromagnet is represented by an arrow. FIG. 5 shows a state in which the direction of the external _magnetic field He is the first direction, and FIG. 6 shows a state in which the direction of the external _magnetic field He is different from the first direction. 5 and 6 each illustrate two states in which the high frequency voltage _VR has different positive and negative values and different timings on the time axis. The magnetization of the third ferromagnetic layer 2 is fixed, for example, in one direction in the plane. The first ferromagnetic layer 20 and the second ferromagnetic layer 1 have, for example, an easy-to-magnetize axis in the direction perpendicular to the film surface.

The first high frequency signal S1 is input to the _first input port p1, and the high frequency voltage _VR having a frequency f is applied to the first ferromagnetic layer 20. The high-frequency voltage _VR periodically changes the magnetic anisotropy _Hk of the first ferromagnetic layer 20, and the magnetization of the first ferromagnetic layer 20 undergoes an aging motion. The precession of the magnetization of the first ferromagnetic layer 20 produces a high frequency magnetic field _HR at frequency f. The high frequency magnetic field _HR is applied to the second ferromagnetic layer 1 of the magnetoresistive sensor 10.

The second high frequency signal S2 is input to the _second input port _p2 , and the high frequency current IR of the frequency f is passed through the magnetoresistive effect element 10. The phase of the high frequency current _IR is matched with, for example, the phase of the high frequency voltage _VR . The phase of the high frequency current _IR may be different from the phase of the high frequency voltage _VR .

The resistance R ₁₀ of the magnetoresistive element 10 changes according to the change in the relative angle between the magnetization of the second ferromagnetic layer 1 and the magnetization of the third ferromagnetic layer 2. 5 and 6 also show the time change of the resistance R ₁₀ of the magnetoresistive effect element 10.

In the examples shown in FIGS. 5 and 6, the first ferromagnetic layer 20 functions as a detection layer for detecting the direction of the external magnetic field. When the direction of the external _magnetic field He changes, the direction of the central axis of the vibration of the magnetization of the first ferromagnetic layer 20 (the axis of rotation of the age difference motion, hereinafter may be simply referred to as the "axis of rotation of magnetization") changes. do. As a result, the timing at which the resistance R ₁₀ of the magnetoresistive effect element 10 becomes maximum or minimum changes, and as shown in FIGS. 5 and 6, the phase of the resistance R ₁₀ of the magnetoresistive effect element 10 changes. When the phase of the resistor R ₁₀ of the magnetic resistance effect element 10 changes, the phase difference Δθ ₁ between the phase of the resistor _{R 10} and the phase of the second high frequency current IR 2 changes, and the DC voltage output from the output port p3. The value of _VDC changes. That is, the magnetic sensor can detect the direction of the external magnetic field He applied to the magnetic sensor by reading the DC voltage _VDC output from the output port _p3 .

Further, the example in which the DC component of the voltage V (output voltage from the magnetic resistance effect element 10) is used for detecting the change in the magnitude of the external magnetic field, the value of the external magnetic field, and the direction of the external magnetic field has been shown. High frequency components of voltage may be used. Since-(A · B / 2) · cos (4πft + Δθ ₁ ), which is a high frequency component of the voltage V, contains the phase difference Δθ ₁ , the phase difference Δθ ₁ can be derived from this high frequency component. If the phase difference Δθ ₁ is known, the magnitude of the external magnetic field can be detected from the phase difference Δθ ₁ . Further, the changes in the phase difference Δθ ₁ and Δθ ₂ with respect to the change in the external magnetic field are steep, and the magnetic sensor can detect the difference in the magnitude of the external magnetic field with high sensitivity.

<Frequency changer>
Next, applications and operations of the magnetoresistive devices 100 and 101 as frequency converters will be described.

When the _first high frequency signal S1 having a frequency f1 is input to the _first input port p1, a high frequency voltage _VR having _a frequency f1 is applied to the first ferromagnetic layer 20. The high-frequency voltage _VR periodically changes the magnetic anisotropy _Hk of the first ferromagnetic layer 20, and the magnetization of the first ferromagnetic layer 20 undergoes an aging motion. The precession of the magnetization of the _first ferromagnetic layer 20 produces a high frequency magnetic field _HR of frequency f1. The high frequency magnetic field _HR is applied to the second ferromagnetic layer 1 of the magnetoresistive sensor 10.

The resistance of the magnetoresistive effect element 10 changes when a high-frequency magnetic field _HR is applied. The resistance R ₁₀ of the magnetoresistive effect element 10 is expressed as, for example, R ₁₀ = C · sin (2πf ₁ t) + R ₀ . C is the amplitude of the resistance R ₁₀ of the magnetoresistive sensor 10. R ₀ is a resistance component of the resistance of the magnetoresistive element 10 that does not depend on the relative angle between the magnetization of the second ferromagnetic layer 1 and the magnetization of the third ferromagnetic layer 2.

When the _second high frequency signal S2 having a frequency f2 is input to the _second input port p2, a high frequency current _IR flows through the magnetoresistive sensor 10. The high frequency current IR is represented by, for example, _IR = _D · sin (2πf ₂ t). C is the amplitude of the high frequency current IR, and f ₂ is the frequency of the second high frequency signal _{S 2} .

The magnetoresistive sensor 10 outputs a voltage V due to the fluctuating resistance _R10 and the high-frequency current IR flowing through the magnetoresistive sensor ₁₀ . The voltage V is expressed by the following equation from Ohm's law.
V = IR x _{R 10}
= (C ・ D / 2) ・ cos (2π ・ (f2 _- f ₁ ) ・ t)-(C ・ D / 2) ・ cos (2π ・ (f ₂ + f ₁ ) ・ t) + D ・ R ₀・sin (2πf ₂ t)

When the passing frequency of the filter F is set so that the signal of the frequency of | f ₂ -f ₁ | passes and the signal of the frequency of f ₂ + f ₁ is cut, the first term on the right side of the above equation is set in the voltage V. (C · D / ₂ ) · cos (2π · (f2 −f ₁ ) · t) can be taken out from the output port p3.

When the passing frequency of the filter F is set so that the signal of the frequency of f ₂ + f ₁ passes and the signal of the frequency of | f ₂ −f ₁ | is cut, the second term on the right side of the above equation is obtained in the voltage V. -(C · D / 2) · cos (2π · (f ₂ + f ₁ ) · t) can be taken out from the output port p3.

As described above, in the magnetic resistance effect devices 100 and 101, high frequency signals of two frequencies are input from the first input port p1 and the second input port p2, and a signal of the difference or sum of the two frequencies is output. It is output from port p3. That is, the magnetoresistive effect devices 100 and 101 function as frequency converters.

As described above, the first embodiment has been described in detail with reference to the drawings by taking the above-mentioned magnetoresistive devices 100 and 101 as an example, but the first embodiment is not limited to this example.

(First modification)
FIG. 7 is a diagram showing a circuit configuration of the magnetoresistive effect device 102 according to the first modification. In the magnetoresistive effect device 102, the same components as those of the magnetoresistive effect devices 100 and 101 are designated by the same reference numerals, and the description thereof will be omitted.

In the magnetoresistive effect device 102, the magnetoresistive element 10 and the first ferromagnetic layer 20 are in contact with each other.

The magnetoresistive device 102 includes signal lines L1 to L4. In FIG. 7, the signal line L2 connects the first ferromagnetic layer 20 and the reference potential terminal pr1, and also connects the magnetoresistive element 10 and the reference potential terminal pr1. The signal line L2 also has the functions of the signal line L2 and the signal line L5 in FIG.

FIG. 8 is an enlarged view of the vicinity of the magnetoresistive element 10 of the magnetoresistive device 102 according to the first modification. The first ferromagnetic layer 20 is on at least one side of the magnetoresistive element 10 in the stacking direction.

The magnetoresistive device 102 has an insulating layer 30 and electrodes 40, 41, 42. The insulating layer 30 may be any as long as it has an insulating property, and the electrodes 40, 41, 42 may be conductors. The insulating layer 30 is sandwiched between, for example, the electrode 40 and the first ferromagnetic layer 20. The insulating layer 30 is, for example, a non-magnetic material and is an oxide containing magnesium such as magnesium oxide (MgO) and spinel (MgAl _{2O 4} ). The electrode 40 is, for example, on the opposite side of the magnetoresistive element 10 with respect to the first ferromagnetic layer 20 in the stacking direction. The electrode 41 is in contact with a surface of the magnetoresistive element 10 opposite to the surface in contact with the first ferromagnetic layer 20. The electrode 42 is in contact with the first ferromagnetic layer 20. The electrode 40 is connected to, for example, the signal line L1. The electrode 41 is connected to, for example, the signal line L3. The electrode 42 is connected to, for example, the signal line L2. A high frequency voltage _VR is applied between the electrode 40 and the electrode 42, and a high frequency current _IR flows between the electrode 41 and the electrode 42.

The magnetoresistive effect device 102 according to the first modification can be used as a magnetic sensor and a frequency converter in the same manner as the magnetoresistive effect devices 100 and 101. Further, since the magnetoresistive device 102 according to the first modification generates the high frequency magnetic field _HR by using the high frequency voltage _VR applied to the first ferromagnetic layer 20, the power consumption can be reduced. Further, the magnetoresistive device 102 according to the first modification can increase the magnetization amplitude of the second ferromagnetic layer 1 by vibrating the second ferromagnetic layer 1 by the high frequency magnetic field _HR , and can increase the magnetization amplitude from the output port p3. The output can be increased.

(Second modification)
FIG. 9 is an enlarged view of the vicinity of the magnetoresistive element 10 of the magnetoresistive device 103 according to the second modification. In the magnetoresistive effect device 103, the same components as those of the magnetoresistive effect device 102 are designated by the same reference numerals, and the description thereof will be omitted.

The magnetoresistive effect device 103 has a metal layer 50. The metal layer 50 is sandwiched between the insulating layer 30 and the first ferromagnetic layer 20. The metal layer 50 has a 5d transition metal element. Examples of the 5d transition metal element include Pt, Au, W, Ta, Ir, Gd and the like. The metal layer 50 is in contact with the insulating layer 30 and the first ferromagnetic layer 20. For example, the insulating layer 30 is an oxide containing magnesium such as magnesium oxide (MgO) and _spinel ( _MgAl2O4 ).

The magnetoresistive effect device 103 according to the second modification has the same effect as the magnetoresistive device 102 according to the first modification. Further, since the metal layer 50 having a large spin-orbit interaction exists between the insulating layer 30 and the first ferromagnetic layer 20, the magnetic anisotropy of the first ferromagnetic layer 20 when a high frequency voltage _VR is applied. The amount of change in sex increases. Since the magnetization of the first ferromagnetic layer 20 undergoes a aging motion based on the change in magnetic anisotropy, when the amount of change in magnetic anisotropy becomes large, the high-frequency magnetic field _HR generated in the first ferromagnetic layer 20 becomes large. Become. As a result, the amplitude of the magnetization of the second ferromagnetic layer 1 by the high frequency magnetic field _HR can be increased, and the output from the output port p3 can be increased.

Here, an example in which the metal layer 50 is applied to the structure in which the magnetic resistance effect element 10 and the first ferromagnetic layer 20 are in contact with each other has been described, but the magnetic resistance effect element 10 and the first ferromagnetic layer 20 are separated from each other. The metal layer 50 may be applied to the magnetoresistive effect device 101 in one embodiment.

(Third modification example)
FIG. 10 is an enlarged view of the vicinity of the magnetoresistive element 10 of the magnetoresistive device 104 according to the third modification. In the magnetoresistive device 104, the same components as those of the magnetoresistive device 102 are designated by the same reference numerals, and the description thereof will be omitted.

The magnetoresistive effect device 104 has a non-magnetic layer 21 and a fourth ferromagnetic layer 22. The fourth ferromagnetic layer 22 is sandwiched between the magnetoresistive element 10 and the first ferromagnetic layer 20. The non-magnetic layer 21 is sandwiched between the first ferromagnetic layer 20 and the fourth ferromagnetic layer 22.

For the non-magnetic layer 21, for example, the same material as the spacer layer 3 can be used. The non-magnetic layer 21 contains, for example, an oxide containing magnesium. When the non-magnetic layer 21 contains an oxide containing magnesium, the magnetic anisotropy of the first ferromagnetic layer 20 and the fourth ferromagnetic layer 22 is increased. The non-magnetic layer 21 is an oxide containing magnesium such as magnesium oxide (MgO) and spinel (MgAl _{2O 4} ). For the fourth ferromagnetic layer 22, for example, the same material as the first ferromagnetic layer 20 can be used, but it is preferable that the saturation magnetization is larger than that of the first ferromagnetic layer 20. The saturation magnetization of the ferromagnetic layer can be changed, for example, by changing the composition of the alloy.

The first ferromagnetic layer 20 and the fourth ferromagnetic layer 22 are magnetically coupled. The magnetic anisotropy of the first ferromagnetic layer 20 changes when a high frequency voltage _VR is applied, and a high frequency magnetic field _HR is generated. The magnetization of the fourth ferromagnetic layer 22 precesses according to the magnetization of the first ferromagnetic layer 20. The magnetization of the fourth ferromagnetic layer 22 receives the high-frequency magnetic field _HR generated in the first ferromagnetic layer 20 and undergoes aging motion to generate the high-frequency magnetic field _HR 1. The high-frequency magnetic field _HR1 generated in the fourth ferromagnetic layer 22 causes the magnetization of the second ferromagnetic layer 1 to precess.

The change in the magnetic anisotropy of the first ferromagnetic layer 20 due to the high frequency voltage _VR becomes larger as the thickness of the first ferromagnetic layer 20 becomes thinner. On the other hand, the higher the amount of magnetization of the fourth ferromagnetic layer 22, the larger the high frequency magnetic field _HR1 . Therefore, it is preferable that the fourth ferromagnetic layer 22 is thicker than the first ferromagnetic layer 20, for example.

The magnetoresistive effect device 104 according to the third modification has the same effect as the magnetoresistive device 102 according to the first modification. Further, since the magnetic resistance effect device 104 has the first ferromagnetic layer 20 and the fourth ferromagnetic layer 22, it is applied to a portion where a high-frequency magnetic field _HR is generated by a change in magnetic anisotropy and a second ferromagnetic layer 1. The function can be divided into the part that produces the high-frequency magnetic field _HR1 . As a result, materials and configurations suitable for each function can be applied to the first ferromagnetic layer 20 and the fourth ferromagnetic layer 22. As a result, the amplitude of the magnetization of the second ferromagnetic layer 1 by the high-frequency magnetic fields _HR and _HR1 can be increased, and the output from the output port p3 can be increased.

Here, an example in which the non-magnetic layer 21 and the fourth ferromagnetic layer 22 are applied to the structure in which the magnetic resistance effect element 10 and the first ferromagnetic layer 20 are in contact with each other has been described, but the magnetic resistance effect element 10 and the first ferromagnetic layer 22 have been described. The non-magnetic layer 21 and the fourth ferromagnetic layer 22 may be applied to the magnetic resistance effect devices 100 and 101 in the first embodiment, which are separated from the layer 20.

Further, as in the magnetoresistive effect device 104A shown in FIG. 11, between the insulating layer 30 and the first ferromagnetic layer 20, between the first ferromagnetic layer 20 and the non-magnetic layer 21, the non-magnetic layer 21 and the fourth strength. The metal layer 50 in the second modification may be provided between the magnetic layer 22 and the magnetic layer 22. The metal layer 50 does not have to be all between them, but may be only between them. The metal layer 50 increases the amount of change in the magnetic anisotropy of the first ferromagnetic layer 20 and the fourth ferromagnetic layer 22.

(Fourth modification)
FIG. 12 is an enlarged view of the vicinity of the magnetoresistive element 10 of the magnetoresistive device 105 according to the fourth modification. In the magnetoresistive device 105, the same components as those of the magnetoresistive device 104 are designated by the same reference numerals, and the description thereof will be omitted.

The magnetoresistive device 105 has a fifth ferromagnetic layer 23. The fifth ferromagnetic layer 23 is located at a position overlapping the magnetoresistive element 10 when viewed from any direction in the plane orthogonal to the laminating direction of the magnetoresistive element 10. FIG. 13 is a view of the magnetoresistive effect device 105 as viewed from the side of the magnetoresistive effect element 10 in the stacking direction. As shown in FIG. 13, the fifth ferromagnetic layer 23 may surround the magnetoresistive element 10. Further, as shown in FIG. 14, the fifth ferromagnetic layer 23 may have a structure that sandwiches the magnetoresistive element 10. In FIGS. 13 and 14, the electrode 41 and the electrode 42 are omitted. For the fifth ferromagnetic layer 23, for example, the same material as the fourth ferromagnetic layer 22 can be used. The magnetization of the fifth ferromagnetic layer 23 receives the high-frequency magnetic field _HR generated in the first ferromagnetic layer 20 and undergoes an aging motion to generate a high-frequency magnetic field. The high-frequency magnetic field generated in the fifth ferromagnetic layer 23 causes the magnetization of the second ferromagnetic layer 1 to precess.

The magnetoresistive effect device 105 according to the fourth modification has the same effect as the magnetoresistive device 104 according to the third modification. Further, since the magnetoresistive device 105 has the fifth ferromagnetic layer 23, a larger high frequency magnetic field can be applied to the second ferromagnetic layer 1. As a result, the magnetoresistive device 105 according to the fourth modification can increase the amplitude of the magnetization of the second ferromagnetic layer 1 and increase the output from the output port p3.

Although FIG. 14 shows an example in which the magnetoresistive element 10 and the fourth ferromagnetic layer 22 are in contact with each other, they may be separated from each other. For example, the magnetoresistive device 105A shown in FIG. 15 further has a non-magnetic layer 24 between the fourth ferromagnetic layer 22 and the magnetoresistive element 10. The non-magnetic layer 24 is also sandwiched between, for example, the fourth ferromagnetic layer 22 and the fifth ferromagnetic layer 23. When the fourth ferromagnetic layer 22 and the magnetoresistive element 10 are separated from each other, it is preferable that the fourth ferromagnetic layer 22 and the fifth ferromagnetic layer 23 are separated from each other. With this configuration, the high-frequency magnetic field applied from the 4th ferromagnetic layer 22 to the 2nd ferromagnetic layer 1 and the high-frequency magnetic field applied from the 5th ferromagnetic layer 23 to the 2nd ferromagnetic layer 1 strengthen each other. become.

(Fifth modification)
FIG. 16 is a diagram schematically showing a circuit configuration of the magnetoresistive effect device 106 according to the fifth modification. In the magnetoresistive device 106, the same components as those of the magnetoresistive device 100 are designated by the same reference numerals, and the description thereof will be omitted.

The magnetoresistive device 106 includes a yoke Y. The yoke Y sandwiches the first ferromagnetic layer 20 when viewed from the plane perpendicular direction of the first ferromagnetic layer 20. The yoke Y contains a soft magnetic material. The yoke Y is, for example, Fe, Co, Ni, an alloy of Ni and Fe, an alloy of Fe and Co, an alloy of Fe and Co and B, and the like.

FIG. 17 is a view of the vicinity of the first ferromagnetic layer 20 of the magnetoresistive effect device 106 as viewed from the plane direction of the first ferromagnetic layer 20. As shown in FIG. 17, the yoke Y may surround the first ferromagnetic layer 20. Further, as shown in FIG. 18, the yoke Y may have a structure that sandwiches the first ferromagnetic layer 20. When viewed from the plane direction of the first ferromagnetic layer 20, there is a gap Gp between the yokes Y.

When an external magnetic field He is applied to the magnetoresistive device 106, the yoke Y _induces a magnetic flux and concentrates the magnetic flux in the gap Gp. The yoke Y applies a magnetic field generated in the gap _Gp by the external magnetic field He to the first ferromagnetic layer 20. The magnetization of the first ferromagnetic layer 20 is affected by the magnetic field generated in the gap Gp. The direction of the magnetic field generated in the gap _Gp changes according to the direction of the external magnetic field He. The magnetoresistive effect device 106 is particularly applicable to a magnetic sensor that _detects the direction of an external magnetic field He.

(6th modification)
FIG. 19 is a diagram schematically showing a circuit configuration of the magnetoresistive effect device 107 according to the sixth modification. In the magnetoresistive effect device 107, the same components as those of the magnetoresistive effect device 100 are designated by the same reference numerals, and the description thereof will be omitted.

In the magnetoresistive effect device 107, the first ferromagnetic layer 20 is located at a position different from the stacking direction of the magnetoresistive element 10. The first ferromagnetic layer 20 sandwiches the magnetoresistive element 10 when viewed from the plane perpendicular direction of the first ferromagnetic layer 20, for example. The first ferromagnetic layer 20 may surround the magnetoresistive element 10, for example.

The magnetoresistive effect device 107 according to the sixth modification has the same effect as the magnetoresistive device 100 according to the first modification. When the first ferromagnetic layer 20 is in the stacking direction of the magnetic resistance effect element 10, the magnetism of the second ferromagnetic layer 1 is efficiently age-shifted by the high-frequency magnetic field _HR generated in the first ferromagnetic layer 20. However, even when the first ferromagnetic layer 20 is located at a position different from the stacking direction of the magnetic resistance effect element 10, the magnetism of the second ferromagnetic layer 1 can be efficiently age-shifted by the high-frequency magnetic field _HR . can.

"Second embodiment"
FIG. 20 is a diagram showing a circuit configuration of the magnetoresistive device 110 according to the second embodiment. The magnetoresistive effect device 110 includes a magnetoresistive effect element 10, a first ferromagnetic layer 20, a first input port p1, a second input port p21, an output port p3, a reference potential terminal pr1, pr2, a capacitor C, an inductor L, and a signal. It has lines L1 to L5. The inductor L is one aspect of the filter F. In the magnetoresistive effect device 110, the same reference numerals are given to the same configurations as those of the magnetoresistive effect device 100, and the description thereof will be omitted.

A direct current _ID is input to the second input port p21. The second input port p21 is different from the second input port p2 according to the first embodiment in which the _second high frequency signal S2 is input in that the direct current _ID is input. For example, a DC power supply PS is connected to the second input port p21. The DC power supply PS may be a DC current source or a DC voltage source. The second input port p21 is a DC application terminal to which a power source for applying a DC current or a DC voltage can be connected to the magnetoresistive effect element 10.

As used herein, the direct current is a current whose direction does not change with time, and includes a current whose magnitude changes with time. Further, the DC voltage is a voltage whose polarity does not change with time, and includes a voltage whose magnitude changes with time.

The direct current _ID input to the second input port p21 is applied to the magnetoresistive element 10 via the signal line L3. Although FIG. 20 shows an example in which the DC current _ID is applied to the magnetoresistive effect element 10, a DC voltage may be applied to the magnetoresistive effect element 10. The current density of the direct current applied to the magnetoresistive sensor 10 is preferably smaller than the oscillation threshold current density of the magnetoresistive sensor 10. The oscillation threshold current density of the magnetic resistance effect element is that when a current with a current density equal to or higher than this value is applied, the magnetization of the second ferromagnetic layer 1 of the magnetic resistance effect element is aged at a constant frequency and a constant amplitude. It is the current density of the threshold at which the motion is started and the magnetic resistance effect element oscillates (the output (resistance value) of the magnetic resistance effect element fluctuates at a constant frequency and a constant amplitude).

<Filter>
The magnetoresistive device 110 according to the second embodiment functions as, for example, a filter.

When the first high frequency signal S1 is input to the _first input port p1, a high frequency voltage _VR is applied to the first ferromagnetic layer 20. The high-frequency voltage _VR periodically changes the magnetic anisotropy _Hk of the first ferromagnetic layer 20, and the magnetization of the first ferromagnetic layer 20 undergoes an aging motion. The precession of the magnetization of the first ferromagnetic layer 20 produces a high frequency magnetic field _HR . The high frequency magnetic field _HR is applied to the second ferromagnetic layer 1 of the magnetoresistive sensor 10.

The magnetization of the second ferromagnetic layer 1 vibrates significantly when the frequency of the high-frequency magnetic field _HR applied to the second ferromagnetic layer 1 is close to the ferromagnetic resonance frequency of the second ferromagnetic layer 1. Further, even when the frequency of the _first high frequency signal S1 input from the first input port p1 is close to the ferromagnetic resonance frequency of the first ferromagnetic layer 20, the high frequency magnetic field applied to the second ferromagnetic layer 1 The _HR becomes large, and the magnetism of the second ferromagnetic layer 1 vibrates greatly.

When the vibration of the magnetization of the second ferromagnetic layer 1 becomes large, the change in the resistance value in the magnetoresistive element 10 becomes large. For example, when a constant DC current _ID is applied to the magnetoresistive sensor 10 from the second input port p21, the change in the resistance value of the magnetoresistive sensor 10 is a change in the potential difference in the stacking direction of the magnetoresistive element 10. Is output from the output port p3. Further, for example, when a constant DC voltage is applied to the magnetoresistive effect element 10 from the second input port p2, the change in the resistance value of the magnetoresistive effect element 10 is regarded as a change in the current value flowing through the magnetoresistive effect element 10. It is output from the output port p3. That is, a signal caused by the vibration of the magnetization of the second ferromagnetic layer 1 is output from the output port p3.

That is, when the frequency of the _first high frequency signal S1 input from the first input port p1 is close to the ferromagnetic resonance frequency of the second ferromagnetic layer 1 or the first ferromagnetic layer 20, the resistance of the magnetic resistance effect element 10 The amount of fluctuation of the value is large, and a large signal is output from the output port p3. On the other hand, when the frequency of the first high frequency signal S ₁ deviates from the ferromagnetic resonance frequency of the second ferromagnetic layer 1 and the first ferromagnetic layer 20, the fluctuation amount of the resistance value of the magnetic resistance effect element 10 increases. It is small and almost no signal is output from the output port p3. That is, the magnetoresistive device 100 functions as a high-frequency filter capable of selectively passing a high-frequency signal of a specific frequency.

Although the second embodiment has been described in detail with reference to the drawings by taking the above-mentioned magnetoresistive device 110 as an example, the second embodiment is not limited to this example.

"Third embodiment"
FIG. 21 is a diagram showing a circuit configuration of the magnetoresistive device 120 according to the third embodiment. The magnetoresistive device 120 includes a magnetoresistive element 10, a first ferromagnetic layer 20, a first input port p1, a capacitor C, a filter F, and signal lines L1, L6 to L8. In the magnetoresistive device 120, the same reference numerals are given to the same configurations as those of the magnetoresistive device 100, and the description thereof will be omitted.

The signal line L1 connects the first input port p1 and the first ferromagnetic layer 20. The signal line L6 connects the signal line L1 and the magnetoresistive effect element 10. The signal line L7 connects the magnetoresistive effect element 10 and the output port p3. The signal line L8 connects the signal line L7 and the reference potential terminal pr3. The reference potential terminal pr3 is the same as the reference potential terminal pr1.

The first input port p1 is connected to the first ferromagnetic layer 20 and the magnetoresistive element 10. The first input port p1 and the first ferromagnetic layer 20 are connected by a signal line L1. The first input port p1 and the magnetoresistive sensor 10 are connected by a part of the signal line L1 and the signal line L6.

A high frequency voltage _VR is applied to the first ferromagnetic layer 20 by the _first high frequency signal S1 input to the first input port p1. When the first high frequency signal S1 is input to the first input port p1, the potential of the _first input port p1 with respect to the reference potential terminal pr3 fluctuates. A high frequency voltage _VR is applied to the first ferromagnetic layer 20 due to the fluctuation of the potential of the first input port p1 with respect to the reference potential terminal pr3. A high frequency magnetic field _HR is generated by the high frequency voltage _VR applied to the first ferromagnetic layer 20. The high frequency magnetic field _HR is applied to the second ferromagnetic layer 1.

The magnetization of the second ferromagnetic layer 1 vibrates in response to the high frequency magnetic field _HR caused by the high frequency voltage _VR . The resistance R ₁₀ of the magnetoresistive element 10 changes (vibrates) due to the vibration of the magnetization of the second ferromagnetic layer 1.

Further, a high frequency current _IR is applied to the magnetoresistive element 10 by the _first high frequency signal S1 input to the first input port p1. When the first high frequency signal S1 is input to the _first input port p1, a high frequency current _IR flows through the signal line L6. The high frequency current _IR flows through the magnetoresistive element 10. A signal caused by the output from the magnetoresistive sensor 10 is output from the output port p3.

In the magnetoresistive device 120 of the third embodiment, the high-frequency voltage _VR applied to the first ferromagnetic layer 20 and the high-frequency current _IR applied to the magnetoresistive element 10 are both transmitted to the _first high-frequency signal S1. It is caused. The first high frequency signal S ₁ is branched into a signal line L1 and a signal line L6, and is input to the first ferromagnetic layer 20 and the magnetoresistive element 10. In the magnetic resistance effect device 100 of the first embodiment, the high frequency voltage _VR applied to the first ferromagnetic layer 20 is caused by the first high frequency signal _{S 1} , and the high frequency current IR applied to the magnetic resistance effect element 10 Is due to the _second high frequency signal S2, which is different from the magnetoresistive effect device 120 of the third embodiment. The magnetoresistive device 120 of the third embodiment has a different source of the high frequency current _IR from the first embodiment, but has the same effect as the magnetoresistive device of the first embodiment.

The magnetoresistive device 120 of the third embodiment can be used as a magnetic sensor or a frequency converter like the magnetoresistive device 100 of the first embodiment. Also, when the magnetoresistive device 120 of the third embodiment is used as a magnetic sensor, it is possible to detect a change in the magnitude of the external magnetic field, the magnitude of the external magnetic field, or the direction of the external magnetic field, as in the first embodiment.

Further, as in the magnetoresistive device 120A shown in FIG. 22, the connection relationship of each component may be changed. The signal line L9 connects the first ferromagnetic layer 20 and the reference potential terminal pr4. The signal line L10 connects the signal line L9 and the magnetoresistive effect element 10. The reference potential terminal pr4 is the same as the reference potential terminal pr1.

(7th modification)
FIG. 23 is a diagram showing a circuit configuration of the magnetoresistive effect device 121 according to the seventh modification. The magnetoresistive device 121 includes a magnetoresistive element 10, a first ferromagnetic layer 20, a first input port p1, a capacitor C, a filter F, and signal lines L1, L5, L11, and L12. In the magnetoresistive effect device 121, the same reference numerals are given to the same configurations as those of the magnetoresistive effect device 100, and the description thereof will be omitted.

The signal line L1 connects the first input port p1 and the first ferromagnetic layer 20. The signal line L11 connects the first ferromagnetic layer 20 and the magnetoresistive element 10. The signal line L5 connects the magnetoresistive effect element 10 and the reference potential terminal pr2. The first input port p1, the first ferromagnetic layer 20, and the magnetoresistive element 10 are connected in series by signal lines L1, L11, and L5. The signal line L12 connects the signal line L11 and the output port p3.

The first input port p1 is connected to the first ferromagnetic layer 20 and the magnetoresistive element 10. The first input port p1 and the first ferromagnetic layer 20 are connected by a signal line L1. The first input port p1 and the magnetoresistive sensor 10 are connected by signal lines L1 and L11. A high frequency voltage _VR is applied to the first ferromagnetic layer 20 by the _first high frequency signal S1 input to the first input port p1. Further, a high frequency current _IR is applied to the magnetoresistive element 10 by the _first high frequency signal S1 input to the first input port p1.

The magnetoresistive effect device 121 of the seventh modification has the same effect as the magnetoresistive effect device 100.

Further, as in the magnetoresistive device 121A shown in FIG. 24, the magnetoresistive element 10 and the first ferromagnetic layer 20 may be directly connected.

(8th modification)
FIG. 25 is a diagram showing a circuit configuration of the magnetoresistive effect device 122 according to the eighth modification. The magnetoresistive device 122 includes a magnetoresistive element 10, a first ferromagnetic layer 20, a first input port p1, a capacitor C, a filter F, a branch D, and a signal line L2, L13, L14, L15, L4, L5. To be equipped. In the magnetoresistive effect device 122, the same reference numerals are given to the same configurations as those of the magnetoresistive effect device 100, and the description thereof will be omitted.

The branch portion D branches the signal. The branch D is, for example, a directional coupler. The signal line L13 is connected to the first input port p1 and the branch portion D. The signal line L14 is connected to the branch portion D and the first ferromagnetic layer 20. The signal line L15 is connected to the branch portion D and the magnetoresistive sensor 10. The signal line L14 is an example of the first signal line. The signal line L15 is an example of a second signal line. The first input port p1 is connected to the signal line L14 and the signal line L15 via the branch portion D.

The first input port p1 is connected to the first ferromagnetic layer 20 and the magnetoresistive element 10. The first input port p1 and the first ferromagnetic layer 20 are connected to each other via signal lines L13 and L14 and a branch portion D. The first input port p1 and the magnetoresistive sensor 10 are connected to each other via signal lines L13 and L15 and a branch portion D. A high frequency voltage _VR is applied to the first ferromagnetic layer 20 by the _first high frequency signal S1 input to the first input port p1. Further, a high frequency current _IR is applied to the magnetoresistive element 10 by the _first high frequency signal S1 input to the first input port p1.

The magnetoresistive effect device 122 of the eighth modification has the same effect as the magnetoresistive effect device 100.

Although the third embodiment has been described in detail with reference to the drawings, the third embodiment is not limited to this example. For example, each of the modifications according to the first embodiment is also applicable to the third embodiment. For example, in the magnetoresistive device according to the third embodiment, the insulating layer 30, the electrode 40, the metal layer 50, the fourth ferromagnetic layer 22, the fifth ferromagnetic layer 23, or the yoke Y can be applied.

"Fourth Embodiment"
FIG. 26 is a diagram showing a circuit configuration of the magnetoresistive device 200 according to the fourth embodiment. The magnetoresistive device 200 includes a magnetoresistive element 10, a first ferromagnetic layer 20, a first input port p11, a capacitor C, an inductor L, signal lines L5, L16 to L18, and an output port p3. In the magnetoresistive device 200, the same reference numerals are given to the same configurations as those of the magnetoresistive device 100, and the description thereof will be omitted.

The signal line L16 connects the magnetoresistive element 10 and the first ferromagnetic layer 20. The signal line L16 is a feedback signal line. The signal line L17 connects the first ferromagnetic layer 20 and the output port p3. The signal line L18 connects the first input port p11 and the signal line L16. The output port p3 outputs the signal output from the magnetoresistive sensor 10.

The first input port p11 is a DC application terminal to which a DC power supply PS for applying a DC current or a DC voltage can be connected to the magnetoresistive effect element 10. For example, a DC power supply PS is connected to the first input port p11, and a DC current _ID is input. The DC power supply PS may be a DC current source or a DC voltage source. The direct current _ID input to the first input port p11 is applied to the magnetoresistive element 10 via a part of the signal line L18 and the signal line L16.

The magnetoresistive device 200 according to the fourth embodiment functions as, for example, an oscillator.

The operation of the magnetoresistive effect device 200 will be described. First, the first signal Sg ₁ , which is a high frequency signal, is generated in the signal line L16. The high frequency signal is, for example, a signal having a frequency of 100 MHz or more. The first signal Sg ₁ is, for example, noise. Noise is generated, for example, when a power source is connected to the first input port p11. A high frequency voltage _VR is applied to the first ferromagnetic layer 20 by the signal Sg ₁ . The high frequency voltage _VR produces a high frequency magnetic field _HR .

The high frequency magnetic field _HR is applied to the second ferromagnetic layer 1. The magnetization of the second ferromagnetic layer 1 vibrates under the high frequency magnetic field _HR . The resistance value of the magnetoresistive element 10 changes due to the vibration of the magnetization of the second ferromagnetic layer 1. The first input port p11 applies a direct current _ID to the magnetoresistive element 10. The direct current _ID flows in the stacking direction of the magnetoresistive element 10. The direct current _ID flows through the signal line L5 to the ground G. The potential of the magnetoresistive sensor 10 changes according to Ohm's law. The signal Sg ₂ , which is a high-frequency signal, is generated according to the change in the potential (change in the resistance value) of the magnetoresistive element 10. The signal Sg ₂ is output from the magnetoresistive effect element 10 to the signal line L16.

A high frequency voltage _VR is applied to the first ferromagnetic layer 20 by the signal Sg ₂ , and the first ferromagnetic layer 20 generates a high frequency magnetic field _HR . The magnetoresistive sensor 10 receives the high-frequency magnetic field _HR and outputs the signal Sg ₃ , which is a high-frequency signal, to the signal line L16. The signal Sg ₃ applies a high frequency voltage _VR to the first ferromagnetic layer 20 again, and the first ferromagnetic layer 20 again generates a high frequency magnetic field _HR . The magnetoresistive device 200 repeats this cycle.

A high-frequency voltage _VR is applied to the first ferromagnetic layer 20 by the high-frequency signal, a high-frequency magnetic field _HR caused by the high-frequency voltage _VR is applied to the second ferromagnetic layer 1, and the magnetic resistance effect element 10 transmits the high-frequency signal. The cycle of output to the signal line L16 is defined as one cycle.

The magnetoresistive device 200 has a large output at a frequency near the ferromagnetic resonance frequency of the second ferromagnetic layer 1 or the first ferromagnetic layer 20, and has a small output at other frequencies. Therefore, with each cycle, the relative intensity of the signal at the frequency near the ferromagnetic resonance frequency increases (frequency filtering is performed) with respect to the signal at the frequency outside the vicinity of the ferromagnetic resonance frequency.

Further, the strength of the signal output from the output port p3 is amplified every time the cycle is repeated under certain conditions. In the magnetoresistive sensor 200, when the intensity of the output signal (for example, signal Sgn ( _n is a natural number of 2 or more)) from the magnetoresistive element 10 reaches the output saturation value of the magnetoresistive element 10, ferromagnetic resonance occurs. A signal with stable intensity at a frequency near the frequency is output from the output port p3. As described above, the magnetoresistive device 200 functions as an oscillator having a large difference in output characteristics between the oscillation band and other bands.

Although the fourth embodiment has been described in detail with reference to the drawings, the configurations and combinations thereof in the fourth embodiment are examples, and the configurations may be added or omitted within a range not deviating from the gist of the present invention. , Replacements, and other changes are possible.

(9th modification)
FIG. 27 is a diagram schematically showing a circuit configuration of the magnetoresistive device 201 according to the ninth modification. In the magnetoresistive device 201 according to the ninth modification shown in FIG. 27, the signal line L16 has a branch portion D, and the output port p3 is connected to the branch portion D via the signal line L19. It is different from the magnetoresistive effect device 200 shown in 26. In the magnetoresistive device 201 shown in FIG. 27, the same reference numerals are given to the same configurations as those of the magnetoresistive effect device 200 shown in FIG. 26, and the description of the common configurations is omitted.

The branch portion D is on the signal line L16. The branch portion D is a portion including a connection point where the signal line L16 and the signal line L19 are connected. The branch portion D may be any as long as it can branch the signal. The branch D is, for example, a directional coupler. The first ferromagnetic layer 20 is connected to the signal line L2 connected to the reference potential terminal pr1 instead of the signal line L17 connected to the output port p3. The signal output from the magnetoresistive effect element 10 flows through the signal line L16, and a part of the signal reaches the output port p3 at the branch portion D.

The magnetoresistive effect device 201 according to the ninth modification has the same effect as the magnetoresistive effect device 200.

(10th modification)
FIG. 28 is a diagram showing a circuit configuration of the magnetoresistive effect device 202 according to the tenth modification. The magnetoresistive effect device 202 according to the tenth modification has a plurality of units U1 to U4 including the magnetoresistive effect element 10 and the first ferromagnetic layer 20. In the magnetoresistive device 202, the same reference numerals are given to the same configurations as those of the magnetoresistive device 200, and the description thereof will be omitted.

The unit U1 has, for example, a magnetoresistive element 10, a first ferromagnetic layer 20, an inductor L, a first input port p11, a reference potential terminal pr2, an output port p3, and signal lines L5, L16, L17, and L18. The units U2 to U4 have a reference potential terminal pr1 instead of the output port p3 of the unit U1, and a signal line L2 instead of the signal line L17 of the unit U1. The number of units U1 to U4 does not matter. The units U1 to U4 are connected in a ring shape by the signal line L16. The signal line L16 connects the magnetoresistive element 10 of different units and the first ferromagnetic layer 20. The output port p3 is connected to the first ferromagnetic layer 20 of at least one unit U1.

First, the first signal Ss, which is a high-frequency signal, flows through one of the signal lines L16. A high frequency voltage _VR is applied to the first ferromagnetic layer 20 by the signal Ss. The first ferromagnetic layer 20 to which the high frequency voltage _VR is applied generates a high frequency magnetic field _HR . The high frequency magnetic field _HR is applied to the second ferromagnetic layer 1 of the unit U1. When the magnetization of the second ferromagnetic layer 1 vibrates, the potential of the magnetoresistive effect element 10 changes (change in resistance value), and the signal SgA ₁ which is a high frequency signal is generated. The signal SgA ₁ is output to the signal line L16.

The signal SgA ₁ is input to the unit U2. The unit U2 outputs the signal SgB ₁ . Further, the signal SgB ₁ is input to the unit U3, and the unit U3 outputs the signal SgC ₁ . Further, the signal SgC ₁ is input to the unit U4, and the unit U4 outputs the signal SgD ₁ . The operation of each of the units U2 to U4 is the same as the operation of the unit U1.

The signal _{SgD 1} produces a high frequency magnetic field HR in the first ferromagnetic layer 20 of the unit U1. The high frequency magnetic field _HR is applied to the second ferromagnetic layer 1 of the unit U1. When the magnetization of the second ferromagnetic layer 1 vibrates, the potential of the magnetoresistive effect element 10 changes (the resistance value changes), and the signal SgA ₂ , which is a high frequency signal, is generated. The magnetoresistive device 202 repeats this cycle.

Each unit U1 to U4 of the magnetoresistive device 202 has a large output at a frequency near the ferromagnetic resonance frequency of the second ferromagnetic layer 1 or the first ferromagnetic layer 20, and has a small output at other frequencies. Therefore, each time the signal passes through each of the units U1 to U4, the second ferromagnetic layer 1 or the second ferromagnetic layer 1 or the signal having a frequency deviating from the vicinity of the ferromagnetic resonance frequency of the second ferromagnetic layer 1 and the first ferromagnetic layer 20. The relative intensity of the signal at a frequency near the ferromagnetic resonance frequency of the first ferromagnetic layer 20 is increased (frequency filtering is performed). As a result, the frequency selectivity of the magnetoresistive device 202 is improved. That is, the magnetoresistive device 202 functions as an oscillator having a large difference in output characteristics between the oscillation band and other bands.

Further, as in the magnetoresistive device 203 shown in FIG. 29, one or more of the signal lines L16 may have a branch portion D leading to the output port p3. Further, in FIGS. 28 and 29, the magnetoresistive effect devices 202 and 203 have a plurality of first input ports p11 (DC application terminals), and the magnetoresistive element 10 of each unit has a plurality of first input ports p11. Although connected to one of them, the magnetoresistive device has one first input port p11 (DC application terminal) common to a plurality of units, and the magnetoresistive element 10 of each unit is one of them. It may be connected to a common first input port p11.

1 2nd ferromagnetic layer 2 3rd ferromagnetic layer 3 Spacer layer 10 Magnetic resistance effect element 20 1st ferromagnetic layer 21, 24 Non-magnetic layer 22 4th ferromagnetic layer 23 5th ferromagnetic layer 30 Insulation layer 40, 41 , 42 Electrode 50 Metal layer 100, 101, 102, 103, 104, 104A, 105, 105A, 106, 107, 110, 120, 120A, 121, 121A, 122, 200, 201, 202, 203 Magnetic resistance effect device C Condenser D Branch F Filter G Ground Gp Gap _HR , HR1 High frequency magnetic field L inductor L1 to L19 Signal line p1, p11 1st input port p2, p21 2nd input port p3 Output port PS DC power supply pr1 to _pr4 Reference potential terminal U1 to U4 unit Y yoke

Claims (18)

It is equipped with a magnetoresistive element and a first ferromagnetic layer.
The magnetoresistive sensor includes a second ferromagnetic layer, a third ferromagnetic layer, and a spacer layer sandwiched between the second ferromagnetic layer and the third ferromagnetic layer.
The first ferromagnetic layer generates a high-frequency magnetic field when a high-frequency voltage is applied.
The high-frequency magnetic field is a magnetoresistive effect device applied to the second ferromagnetic layer. The magnetoresistive effect device according to claim 1, wherein the first ferromagnetic layer is on at least one side in the laminating direction of the magnetoresistive element. Further equipped with a metal layer and an insulating layer,
The metal layer is sandwiched between the insulating layer and the first ferromagnetic layer.
The magnetoresistive effect device according to claim 1 or 2, wherein the metal layer contains a 5d transition metal element. Further equipped with an insulating layer and electrodes,
The electrode is on the opposite side of the magnetoresistive element with respect to the first ferromagnetic layer in the stacking direction of the magnetoresistive element.
The magnetoresistive effect device according to claim 2, wherein the insulating layer is sandwiched between the electrode and the first ferromagnetic layer. Further provided with a non-magnetic layer and a fourth ferromagnetic layer,
The fourth ferromagnetic layer is sandwiched between the magnetoresistive element and the first ferromagnetic layer.
The non-magnetic layer is sandwiched between the first ferromagnetic layer and the fourth ferromagnetic layer.
The magnetoresistive effect device according to any one of claims 1 to 4, wherein the fourth ferromagnetic layer is thicker than the first ferromagnetic layer. The magnetoresistive device according to claim 5, wherein the non-magnetic layer contains an oxide containing magnesium. Further equipped with a fifth ferromagnetic layer,
One of claims 1 to 6, wherein the fifth ferromagnetic layer is located at a position overlapping the magnetoresistive element when viewed from any direction in the plane orthogonal to the laminating direction of the magnetoresistive element. The magnetoresistive effect device described in the section. The magnetoresistive device according to any one of claims 1 to 7, wherein a high frequency current is applied to the magnetoresistive element. Further equipped with a first input port and a second input port,
The first input port is connected to the first ferromagnetic layer, and the high frequency voltage is applied to the first ferromagnetic layer by the first high frequency signal input to the first input port.
The magnetism according to claim 8, wherein the second input port is connected to the magnetoresistive element, and the high-frequency current is applied to the magnetoresistive element by a second high-frequency signal input to the second input port. Resistive effect device. With a first input port
The first input port is connected to the first ferromagnetic layer and the magnetoresistive element.
The high frequency voltage is applied to the first ferromagnetic layer by the first high frequency signal input to the first input port.
The magnetoresistive device according to claim 8, wherein the high-frequency current is applied to the magnetoresistive element by the first high-frequency signal input to the first input port. The magnetoresistive device according to claim 10, wherein the first input port, the first ferromagnetic layer, and the magnetoresistive element are connected in series. Further equipped with a first signal line and a second signal line,
The first input port is connected to the first signal line and the second signal line.
The first signal line is connected to the first ferromagnetic layer.
The magnetoresistive effect device according to claim 10, wherein the second signal line is connected to the magnetoresistive element. With more yoke
One of claims 1 to 12, wherein the yoke sandwiches the first ferromagnetic layer when viewed from the plane direction of the first ferromagnetic layer, and applies a magnetic field generated in the gap to the first ferromagnetic layer. The magnetoresistive effect device according to paragraph 1. A signal line connected to the magnetoresistive element and the first ferromagnetic layer,
An output port to which the signal output from the magnetoresistive sensor is output, and an output port.
The magnetoresistive device according to any one of claims 1 to 7, further comprising a direct current application terminal to which a power source for applying a direct current or a direct current voltage can be connected to the magnetoresistive element. It has a plurality of units having the magnetoresistive element and the first ferromagnetic layer, respectively.
A plurality of signal lines connected to the magnetoresistive sensor of each of the plurality of units and connected between different units, respectively.
An output port to which a signal output from any of the plurality of units is output, and an output port.
With one DC application terminal or multiple DC application terminals,
The magnetoresistive sensor of each of the plurality of units is connected to one of the one DC application terminal or the plurality of DC application terminals.
The one DC application terminal or the plurality of DC application terminals can be connected to a power source for applying a DC current or a DC voltage to the connected magnetoresistive element.
Claim 1 in which each of the plurality of signal lines connects the magnetoresistive element of a different unit and the first ferromagnetic layer, and the plurality of units are annularly connected by the plurality of signal lines. The magnetoresistive effect device according to any one of 7 to 7. A magnetic sensor having the magnetoresistive effect device according to any one of claims 1 to 13. A frequency converter having the magnetoresistive effect device according to any one of claims 1 to 13. A filter having the magnetoresistive effect device according to any one of claims 1 to 7.

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