JP6774124B2 - Magneto-resistive element, magnetic head and magnetic reproduction device using the magnetoresistive element - Google Patents

Description

The present invention relates to an element utilizing the plane-directed magnetic resistance effect (CPPGMR) of a thin film having a three-layer structure of ferromagnetic metal / non-magnetic metal / ferromagnetic metal, and particularly above and below the MgTIO layer as the non-magnetic metal layer. The present invention relates to a magnetic resistance element using a non-magnetic spacer layer in which a conductive non-magnetic metal layer is arranged on both layers.

The element utilizing the Current perpendicular to plane Giant Magnetoresistance (CPPGMR) is composed of a thin film having a three-layer structure of ferromagnetic metal / non-magnetic metal / ferromagnetic metal, and is a reading head for magnetic disks. Expected for use. Research has been conducted on devices using a Whistler alloy with a large spin polarization rate as a ferromagnetic metal, and Cu, which is a face-centered cubic (fcc) metal, is used as a spacer layer (layer of non-magnetic metal). It is proposed to be used, for example, in Patent Documents 1 and 2. Further, it has been proposed in Non-Patent Documents 1 and 2, for example, that a Whistler alloy Co ₂ FeGa _0.5 Ge _0.5 (CFGG) is used for the magnetic layer and Ag, which is a face-centered cubic lattice structure metal, is used as the spacer layer. ing.

Further, Non-Patent Document 3 discloses that when a spacer layer having an fcc structure of Ag or Cu is used, the magnetoresistive output changes significantly depending on the orientation of the Whistler alloy of the ferromagnetic layer. This is because the lattice strain of the bcc-based Whistler alloy and fcc Ag or Cu changes greatly depending on the crystal orientation of the Whistler alloy. As a result, when Ag is used, the (001) plane of the Whistler alloy is used, and when Cu is used. Discloses that high reluctance can be obtained when the (011) plane of the Whistler alloy forms an interface with the spacer layer. Here, (001) and (011) are Miller indexes, which are indexes for describing the crystal plane and the direction in the lattice of the crystal.
However, due to the lattice strain of the Whistler alloy having a bcc group structure and the Ag and Cu having a fcc structure and the magnetic conduction dependence due to their crystal orientations, the reluctance output as predicted from the theoretical calculation is obtained. Absent.

On the other hand, when the L2 ₁ ordered alloy Cu2RhSn or the B2 type ordered alloy NiAl having the same bcc group crystal structure as the Whistler alloy is used for the spacer layer, the consistency at the interface of the band structure is improved and the magnetism is larger. There is a theoretical prediction that a resistance effect will be obtained. Therefore, research has been conducted based on this theoretical prediction, and in Patent Documents 3 and 4 according to the proposals of the present inventors, a Whistler alloy is used as a magnetic layer and an L2 ₁ type or B2 type ordered alloy is used as a spacer layer. The CPPGMR used in the above is disclosed. However, in the inventions of Patent Documents 3 and 4, the effect as predicted from the theoretical calculation is not obtained. It is considered that the reason for this is that since these alloys contain relatively heavy elements Rh and Sn or magnetic elements Ni, the magnetoresistive effect is weakened by the effects of strong spin-orbit scattering and spin scattering.

JP-A-2007-59927 Japanese Unexamined Patent Publication No. 2008-52840 Japanese Unexamined Patent Publication No. 2010-212631 Japanese Patent No. 5245179 WO2016 / 017612 A1

Appl. Phys. Lett. 98, 152501 (2011). J. Appl. Phys. 113, 043901 (2013). Jiamin Chen, Songtian Li, T. Furubayashi, Y. K. Takahashi and K. Hono, J. Appl. Phys. 115, 233905 (2014)

The present invention solves the above-mentioned problems, and is a device utilizing the orthogonal magnetoresistive effect (CPPGMR) of a thin film having a three-layer structure of ferromagnetic metal / non-magnetic metal / ferromagnetic metal, as compared with the conventional structure. Another object of the present invention is to provide a magnetoresistive element that exhibits a high magnetoresistive output.

The present invention is a face- to- plane magnetoresistive element having the following configuration in order to solve the above problems.
As shown in FIG. 1, for example, the plane-directed magnetic resistance element of the present invention is sandwiched between the lower ferromagnetic layer 13 and the upper ferromagnetic layer 15 made of a Whistler alloy, and the lower ferromagnetic layer 13 and the upper ferromagnetic layer 15. in the orthogonal direction magnetoresistive element and a spacer layer 14, a spacer layer 14 _{Mg 1-x Ti x O y} (0.5 ≦ x ≦ 1.0,0.8 ≦ y ≦ 1.2) and It is a non-magnetic spacer layer made of a conductive non-magnetic metal and does not have an interfacial protection layer containing a nitrogen element .

Here, the conductive nonmagnetic metal, but across the sides of the upper and lower _Mg 1-x _Ti x _{O y} of the spacer layer 14 of conductive nonmagnetic metal layer 3-layer structure spacers (e.g., Ag / MTO / Ag) It may be a layer structure that is not clearly separated into a three-layer structure and has a structure in which Mg _1-x T _{x Oy} and a conductive non-magnetic metal are mixed.
As shown in FIG. 1, for example, the plane-directed magnetic resistance element of the present invention is sandwiched between the lower ferromagnetic layer 13 and the upper ferromagnetic layer 15 made of a Whistler alloy, and the lower ferromagnetic layer 13 and the upper ferromagnetic layer 15. in the orthogonal direction magnetoresistive element and a spacer layer 14, a spacer layer 14 _{Mg 1-x Ti x O y} (0.5 ≦ x ≦ 1.0,0.8 ≦ y ≦ 1.2) and , characterized in that the two layers of the upper and lower of the Mg _1-x Ti _x O _y conductive nonmagnetic metallic layer, along with a non-magnetic spacer layer which are arranged, does not have an interface protective layer containing nitrogen element And. In the plane-directed magnetic resistance element of the present invention, preferably, the conductive non-magnetic metal or the conductive non-magnetic metal layer is at least one non-magnetic material selected from Ag, Mg, Al, Zn, Ti, V, and Cu. It should consist of magnetic metal elements.
In the orthogonal direction magnetoresistive element of the present invention, preferably, the _{Mg 1-x Ti x O y} (0.5 ≦ x ≦ 1.0,0.8 ≦ y ≦ 1.2) is _Mg 0.2 Ti _{It should} be _0.8 O.

As shown in FIG. 1, for example, the surface orthogonal magnetoresistive element of the present invention is placed on a substrate 11 which is at least one type of a surface oxide Si substrate, a silicon substrate, a glass substrate, a metal substrate, and an MgO substrate, and a substrate 11. The base layer 12 to be formed and the above-mentioned magnetoresistive sensor in the plane direction laminated on the base layer 12, and the base layer 12 is at least one type selected from the group consisting of Ag, Al, Cu, Au, and Cr. It is characterized in that the crystal direction for epitaxial growth of the Whistler alloy is the (001) direction .

In the plane-directed magnetoresistive element of the present invention, preferably, the lower ferromagnetic layer 13 and the upper ferromagnetic layer 15 are Whistler alloys represented by the composition formula of Co ₂ AB, and A is Cr, Mn, Fe, or a mixture of two or more of these so that the total amount is 1, said B is Al, Si, Ga, Ge, In, Sn, or two or more of these are total. It is preferable to include a mixture so that the amount becomes 1.
In the orthogonal direction magnetoresistive element of the present invention, preferably with the lower ferromagnetic layer 13 and the upper ferromagnetic layer 15 is made of a Heusler ferromagnetic alloy having at least one of the B2 ordered structure or L2 ₁ ordered structure, Heusler Ferromagnetic alloys are Co ₂ Fe (Ga _x Ge _1-x ) (0.25 <x <0.6), Co ₂ FeAl _1-x Si _x (0.0 ≦ x ≦ 1.0), Co ₂ Fe. Including a Whistler ferromagnetic alloy selected from _1-x Mn _x Si (0.0 ≦ x ≦ 1.0) or Co ₂ Fe _1-x Mn _x Ge (0.0 ≦ x ≦ 1.0) Good.

In the orthogonal magnetoresistive element of the present invention, it is preferable that a base layer 12b, which is an electrode for measuring magnetic resistance, is further sandwiched between the base layer 12 and the lower ferromagnetic layer 13.
In the face-to-plane magnetoresistive element of the present invention, preferably, the cap layer 16 for surface protection laminated on the upper ferromagnetic layer 15 is provided, and the cap layer 16 is Ag, Al, Cu, Au, Ru. And at least one metal or alloy selected from the group consisting of Pt.
In the plane-directed magnetoresistive element of the present invention, a pinning layer provided above the upper ferromagnetic layer 15 or below the lower ferromagnetic layer 13, and the pinning layer is an IrMn alloy or a PtMn alloy. It is preferable that the layer is an antiferromagnetic material such as.
In the plane-directed magnetic resistance element configured in this way, the state in which the upper ferromagnetic layer and the lower ferromagnetic layer are magnetized antiparallel is stabilized by suppressing the magnetization reversal of the upper ferromagnetic layer by exchange anisotropy. Can be magnetized.

As shown in FIG. 1, for example, the plane-directed magnetic resistance (CPPGMR) element of the present invention has a structure in which a spacer layer 14 is arranged between whistler alloy thin films (13, 15), and the Whistler alloy thin film is B2. It is composed of a Heusler ferromagnetic alloy having at least one of a regular structure or an L2 ₁ regular structure, and the Whistler ferromagnetic alloy is Co ₂ Fe (Ga _x Ge _1-x ) (0.25 <x <0.6). Co ₂ FeAl _1-x Si _x (0.0 ≦ x ≦ 1.0), Co ₂ Fe _1-x Mn _x Si (0.0 ≦ x ≦ 1.0), or Co ₂ Fe _1-x Mn _x Ge is a Heusler ferromagnetic alloy selected from (0.0 ≦ x ≦ 1.0), the spacer layer 14 _{Mg 1-x Ti x O y} (0.5 ≦ x ≦ 1.0,0.8 ≦ It is characterized in that it is composed of y ≦ 1.2) and a conductive non-magnetic metal, and does not have an interface protection layer containing a nitrogen element .
Here, in Co ₂ Fe (Ga _x Ge _1-x ), the spin polarizability decreases both when the ratio x of Ga is 0.25 or less and when the ratio x of Ga is 0.6 or more. There is an inconvenience that the magnetic resistance decreases. Preferably, the proportion x of Ga at (Ga _x Ge _1-x ) is preferably between 0.25 and 0.6, more preferably between 0.45 and 0.55.

In the present invention, Mg _1-x Ti _{x Oy} (0.5 ≤ x) is used as a material that does not contain the relatively heavy elements Rh / Sn and the magnetic element Ni as in the conventional example, has a low electrical resistivity, and is suitable for the spacer layer. By using ≤1.0, 0.8≤y≤1.2) for the spacer layer, a higher amount of change in magnetoresistance than when the Ag spacer layer is used can be obtained.
Therefore, the CPPGMR element using the MTO of the present invention can be manufactured, and a high magnetoresistive output can be provided. Further, it is suitable for use in a magnetic head and a magnetic reproduction device using the magnetoresistive element of the present invention.

It is a structural schematic diagram of the magnetoresistive element by one Embodiment of this invention. It is sectional drawing which added the electrode for electric resistance measurement with respect to the magnetic field to the CPPGMR element by one Embodiment of this invention. It is a figure explaining the dependence of the electric resistance and the electric resistance per element area with respect to the applied magnetic field of the element which used Mg _0.2 Ti _0.8 O (MTO) for the spacer layer. The distribution diagram of each element in the device obtained by the energy dispersive X-ray analysis method using the cross-sectional transmission electron microscope of the device using Mg _0.2 Ti _0.8 O (MTO) as the spacer layer is shown. It is explanatory drawing of the magnetic resistance change rate with respect to the film thickness of the MTO layer. It is explanatory drawing of the electric resistance change amount per element unit area with respect to the film thickness of the MTO layer.

Hereinafter, the present invention will be described with reference to the drawings.
FIG. 7 is a schematic structural diagram of a magnetoresistive element according to an embodiment of the present invention. In the figure, in the magnetoresistive element, the substrate 11, the base layer 12, the lower ferromagnetic layer 13, the spacer layer 14, the upper ferromagnetic layer 15, and the cap layer 16 are laminated in this order.

For the substrate 11, for example, a single crystal MgO substrate is used, but the substrate is not particularly limited to the single crystal MgO substrate, and Si, a metal, an alloy or the like in which the Whistler alloy layer is polycrystalline may be used as the substrate. As the substrate 11, a surface oxide Si substrate may be inexpensive, but a silicon substrate for semiconductor manufacturing may be used, or a glass substrate or a metal substrate may be used. Even if these materials are used for the substrate 11, a high magnetoresistive ratio can be obtained as a magnetoresistive element.

The base layer 12 serves as an electrode for measuring magnetic resistance, and for example, a metal containing at least one kind such as Ag, Al, Cu, Au, and Cr, or an alloy of these metal elements is used. The base layer 12 may have a two-layer structure in which another base layer 12a is further added under the base layer 12b, or a multi-layer structure having three or more layers.
The alignment layer may be provided below the base layer 12. The alignment layer has an action of orienting the Whistler alloy layer in the (100) direction, and for example, a layer containing at least one of MgO, TiN, and NiTa alloy is used.

The lower ferromagnetic layer 13 and the upper ferromagnetic layer 15 are Whistler alloys represented by the composition formula of Co ₂ AB, and A is Cr, Mn, Fe, or two or more of these in a total amount. B is a mixture of Al, Si, Ga, Ge, In, Sn, or two or more of these so as to have a total amount of 1. As the whisler alloy, Co ₂ Fe (Ga _x Ge _1-x ) (0.25 <x <0.6) (CFGG) is particularly preferable, but up to now, a large amount of change in magnetic resistance × element area ΔRA has been obtained by CPPGMR. Co ₂ FeAl _1-x Si _x (0.0 ≦ x ≦ 1.0), Co ₂ Fe _1-x Mn _x Si (0.0 ≦ x ≦ 1.0), or Co ₂ Fe _{1- It} may be _x Mn _x Ge (0.0 ≦ x ≦ 1.0). For the upper ferromagnetic layer and the lower ferromagnetic layer, one kind of Whistler alloy may be used, or two or more kinds of Whistler alloys or other metals or alloys may be combined.

The spacer layer 14 may have conductive non-magnetic metal layers 14a and 14c using non-magnetic metals on the contact surfaces between the lower ferromagnetic layer 13 and the upper ferromagnetic layer 15, respectively. The spacer layer 14 is conductive nonmagnetic metal layer 14a, an intermediate layer 14b sandwiched by 14c _{is, Mg 1-x Ti x O} y (0.5 ≦ x ≦ 1.0,0.8 ≦ y ≦ 1. 2) is preferable. Here, when x is 0.5 or less, it becomes difficult to obtain conductivity in the intermediate layer 14b. When x is 1.0, it becomes Ti _{x Oy} , and the binary element composition does not contain Mg. When y is less than 0.8, there is an inconvenience that the amount of change in magnetic resistance becomes small because the electrical resistivity of the intermediate layer 14b is too low. If y exceeds 1.2, there is a disadvantage that the electrical resistivity of the intermediate layer 14b is too high to obtain sufficient conductivity.
Since the thickness of the spacer layer 14 is, for example, 0.1 nm to 20 nm, these intermetallic compounds form about 1 to 200 metal atomic layers.

The cap layer 16 is made of a metal or alloy for surface protection. For the cap layer 16, for example, a metal containing at least one kind such as Ag, Al, Cu, Au, Cr and the like, and an alloy of these metal elements are used. Each of the base layer 12, the spacer layer 14, and the cap layer 16 may use one kind of material, or may be a laminate of two or more kinds of materials.

FIG. 1 is a schematic cross-sectional view of a CPPGMR device according to an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view of a CPPGMR device according to an embodiment of the present invention to which an electrode for measuring electrical resistance to a magnetic field is added. In FIG. 2, a single crystal MgO substrate is used as the substrate 11, Cr and Ag are laminated from below on the base layer 12, and a Whistler alloy Co ₂ FeGa _0.5 Ge is formed on the lower ferromagnetic layer 13 and the upper ferromagnetic layer 15. _0.5 (CFGG) is used. As for the spacer layer 14, Ag is used for the conductive non-magnetic metal layers 14a and 14c, and Mg _0.2 Ti _0.8 O (MTO) is used for the intermediate layer 14b. The cap layer 16 is made by laminating Ag and Ru from below.

In the element shown in FIG. 2, from the bottom on the MgO substrate plate, Cr (10) / Ag (100) / CFGG (10) / Ag (1) / MTO (2.2) / Ag (1) / CFGG ( The film was formed by a sputtering method with a film structure of 10) / Ag (5) / Ru (8) and the number in parentheses is the film thickness (nm).
In order to improve the crystal structure of the CFGG thin film, the upper CFGG layer was formed, annealed at 550 ° C. in a vacuum in a sputtering chamber, and then Ag (5) / Ru (8) was laminated.

Next, the details of the element structure of FIG. 2 will be described. In FIG. 2, those having the same action as those in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted. In the figure, the silicon oxide layer 17 is provided around the lower ferromagnetic layer 13, the spacer layer 14, the upper ferromagnetic layer 15, and the cap layer 16 shown in FIG. 1, and is laminated on the base layer 12b of Ag. ing. The copper electrode layer 18 is laminated on the silicon oxide layer 17 and the cap layer 16. The constant current source 19 is connected to the base layer 12b of Ag and the copper electrode layer 18 by the conducting wires 20a and 20b, and a constant current flows in the direction perpendicular to the film surface of the CPPGMR element. The voltmeter 21 is connected to the base layer 12b of Ag and the copper electrode layer 18 by the conducting wires 22a and 22b, and measures the voltage generated in the direction perpendicular to the film surface of the CPPGMR element. Since the electrical resistance in the direction perpendicular to the film surface of the CPPGMR element can be measured from the current value of the constant current source 19 and the measured voltage value of the voltmeter 21, the change in the electrical resistance of the CPPGMR element with respect to the magnetic field can be investigated.

In order to measure the electrical resistance of the element configured in this way in the direction perpendicular to the film surface, fine processing as shown in FIG. 2 is performed, electrodes are further attached, and the change in electrical resistance with respect to the magnetic field applied in the in-plane direction. I checked. FIG. 3 is a diagram in which the electric resistance R per unit area of the element and the electric resistance RA per unit area of the element are plotted against the external magnetic field Hex.

FIG. 3 is an example diagram for explaining the change in electrical resistance × element area with respect to the applied magnetic field of an element using Mg _0.2 Ti _0.8 O (MTO) as the spacer layer, and the horizontal axis is the applied magnetic field H (kA). / M), the vertical axis is electrical resistance [Ω] and electrical resistance × element area [mΩ · μm ² ]. When the applied magnetic field H (kA / m) is increased from -80 kA / m to + 80 kA / m, it is about 207 [mΩ · μm ² ] from -80 kA / m to -40 kA / m, and from -40 kA / m to -8 kA / m. From 207 to 236 [mΩ · μm ² ], gradually increase from -8 kA / m to + 1 kA / m, stepwise increase from 236 to 297 [mΩ · μm ² ], and from + 1 kA / m to + 4 kA / m. Up to m, it shows an almost constant value at about 297 [mΩ · μm ² ]. When the applied magnetic field is further increased, it gradually decreases from 297 to 255 [mΩ · μm ² ] from + 4 kA / m to + 20 kA / m, then decreases to 213 [mΩ · μm ² ] near + 20 kA / m, and from + 20 kA / m. Up to + 40 kA / m, it gradually decreases from 213 to 208 [mΩ · μm ² ], and from + 40 kA / m to + 80 kA / m, it becomes about 207 [mΩ · μm ² ] again. When the applied magnetic field H (kA / m) is decreased from +80 kA / m to -80 kA / m, the applied magnetic field H has a curve substantially symmetric with the case where the applied magnetic field H is increased with 0 kA / m as the center line. ..
A value of ΔRA = 90 mΩ · μm ² was obtained as the magnetic resistance change rate of 43% and the resistance change amount per unit element area.

FIG. 4 shows a distribution diagram of each element Ag, O, Mg, and Ti in the device obtained by the energy dispersive X-ray analysis method using the cross-section transmission electron microscope of the device shown in FIG. It has been shown that the spacer layer consists of Ag and MTO. However, the structure is different from the design of the three-layer structure of Ag / MTO / Ag, and Ag is gathered in almost one layer and non-uniformity is observed depending on the location. It is considered that this is due to the diffusion of atoms by annealing after film formation. However, a large ΔRA was obtained even with such a structure, indicating that it is effective to use a spacer layer composed of Ag and MTO.

In the device having the same structure as that of Example 1, the influence of the spacer layer was investigated by changing the film thickness of MTO. That is, from the bottom on the MgO substrate plate, Cr (10) / Ag (100) / CFGG (10) / Ag (1) / MTO (t) / Ag (1) / CFGG (10) / Ag (5) / The film was formed by a sputtering method with a film structure of Ru (8) and the number in parentheses is the film thickness (nm). Heat treatment and microfabrication were performed under the same conditions as in Example 1, and the magnetic field dependence of the electrical resistance was measured.

FIG. 5 shows a plot of the rate of change in magnetoresistance with respect to the thickness t _MTO (nm) of the MTO layer which is the intermediate layer 14b. When t _MTO = 2.2 nm, the maximum reluctance rate of change of 30% on average was obtained. Further, assuming that the average value of 20% is set as the boundary value as the maximum rate of change in magnetic resistance, the range of 2.1 nm ≦ t _MTO ≦ 2.4 nm is preferable. Further, assuming that the average value of 10% is set as the boundary value as the maximum rate of change in magnetic resistance, the range of 2.0 nm ≦ t _MTO ≦ 2.7 nm is preferable. Further, FIG. 6 shows a plot of the resistance change amount ΔRA per unit element area with respect to t _MTO (nm). When t _MTO = 2.1 nm, the maximum ΔRA with an average value of 87 mΩ · μm ² was obtained.

In order to investigate the effect of the Ag layer as the conductive non-magnetic metal layers 14a and 14c inserted into the spacer layer, an element using only the MTO which is the intermediate layer 14b as the spacer layer was prepared. That is, from the bottom on the MgO substrate plate, Cr (10) / Ag (100) / CFGG (10) / MTO (3.3) / CFGG (10) / Ag (5) / Ru (8), in parentheses. The number is the film thickness (nm), and the film was formed by the sputtering method. The same heat treatment and microfabrication as in Examples 1 and 2 were performed, and the dependence of the electric resistance on the applied magnetic field was measured. As a result, the rate of change in magnetic resistance was 0.3%, which was lower than that of Examples 1 and 2.

In the above embodiment, the epitaxial film oriented in the (001) direction is shown, but the crystal orientation is not limited to this, and (110), (111), (211) and the like are appropriately used. It may be an epitaxial film oriented in the direction of. Further, the structure of the substrate is not limited to a single crystal, but may be a polycrystal. Even in the case of polycrystal, the crystal orientation may be oriented in an appropriate direction such as (001), (110), (111), (211), or may not be oriented at all.

In addition to the structure shown in FIG. 1, a layer of antiferromagnets such as IrMn alloy and PtMn alloy is added as a pinning layer on the upper ferromagnetic layer, and the magnetization reversal of the upper ferromagnetic layer is suppressed by exchange anisotropy. Therefore, it is possible to stabilize the state in which the upper ferromagnetic layer and the lower ferromagnetic layer are magnetized antiparallel. The pinning layer may be inserted below the lower ferromagnetic layer.
Further, in the above embodiment, Ag layers are arranged on both sides of the MgTIO layer as the conductive non-magnetic metal layers 14a and 14c, but the present invention is not limited to this, and this layer is conductive. Any non-magnetic metal may be used, and in addition to Ag, Mg, Al, Zn, Ti, V, Cu may be used. Further, the conductive non-magnetic metal layers 14a and 14c and the MgTIO layer may be spacers having a clear three-layer structure (for example, Ag / MTO / Ag), or have a layer structure that is not clearly separated into the three-layer structure. Further, a layer structure having a structure in which Mg _1-x T _{x Oy} and a conductive non-magnetic metal are mixed may be used.

The element utilizing the surface orthogonal magnetoresistive effect (CPPGMR) of the present invention is suitable for use as a reading head for a magnetic disk, and can also be used for detecting fine magnetic information.

11 Substrate 12a, 12b Underlayer 13 Lower ferromagnetic layers 14a, 14b, 14c Spacer layer 15 Upper ferromagnetic layers 16a, 16b Cap layer

Claims (14)

In a plane-directed magnetic resistance element provided with a lower ferromagnetic layer and an upper ferromagnetic layer made of a Whisler alloy and a spacer layer sandwiched between the lower ferromagnetic layer and the upper ferromagnetic layer.
Together with the spacer layer is a _{Mg 1-x Ti} x O y nonmagnetic spacer layer made of (0.5 ≦ x ≦ 1.0,0.8 ≦ y ≦ 1.2) and the conductive non-magnetic metal, nitrogen A face- to- plane magnetoresistive element that does not have an element-containing interfacial protective layer . The plane perpendicular magnetic resistance according to claim 1 , wherein the conductive non-magnetic metal is composed of at least one non-magnetic metal element selected from Ag, Mg, Al, Zn, Ti, V, and Cu. element. In a plane-directed magnetic resistance element provided with a lower ferromagnetic layer and an upper ferromagnetic layer made of a Whisler alloy and a spacer layer sandwiched between the lower ferromagnetic layer and the upper ferromagnetic layer.
The spacer layer is, Mg and _{1-x Ti x O y (} 0.5 ≦ x ≦ 1.0,0.8 ≦ y ≦ 1.2), both layers of the upper and lower of the _Mg 1-x _Ti x _{O y} the orthogonal direction magnetoresistive element characterized by having no conductive nonmagnetic metallic layer, along with a non-magnetic spacer layer which is arranged, the interface protective layer containing nitrogen element. The plane perpendicular magnetism according to claim 3 , wherein the conductive non-magnetic metal layer is composed of at least one non-magnetic metal element selected from Ag, Mg, Al, Zn, Ti, V, and Cu. Resistive element. Claim _{1 characterized in that the} Mg _1-x Ti _x O _y (0.5 ≦ x ≦ 1.0, _0.8 ≦ y ≦ 1.2) is Mg _0.2 Ti _0.8 O. Item 4. The orthogonal magnetoresistive element according to any one of 4 to 4. Surface oxide substrate, silicon substrate, glass substrate, metal substrate, MgO substrate, which is at least one type of substrate,
The surface orthogonal magnetoresistive element according to any one of claims 1 to 5 , wherein the base layer is formed on the substrate and the base layer is laminated.
The underlying layer includes Ag, Al, Cu, Au, at least one metal or alloy selected from the group consisting of Cr, crystal direction of epitaxial growth of the Heusler alloy is characterized by a (001) direction Planodirectional magnetic resistance element. The lower ferromagnetic layer and the upper ferromagnetic layer are Whistler alloys represented by the composition formula of Co ₂ AB, and the total amount of A is Cr, Mn, Fe, or two or more of these. The B is characterized by containing Al, Si, Ga, Ge, In, Sn, or a mixture of two or more of these so that the total amount is 1. The surface perpendicular magnetic resistance element according to any one of claims 1 to 6 . The lower ferromagnetic layer and the upper ferromagnetic layer, it becomes a Heusler ferromagnetic alloy having at least one of the B2 ordered structure or L2 ₁ ordered structure, the Heusler ferromagnetic alloy _{Co 2 Fe (Ga x Ge 1} -x) (0.25 <x <0.6), Co ₂ FeAl _1-x Si _x (0.0 ≦ x ≦ 1.0), Co ₂ Fe _1-x Mn _x Si (0.0 ≦ x ≦ 1. 0), or the plane-directed magnetic resistance according to claim 8, which comprises a Whistler ferromagnetic alloy selected from Co ₂ Fe _1-x Mn _x Ge (0.0 ≦ x ≦ 1.0). element. The surface according to any one of claims 1 to 8 , wherein a base layer, which is an electrode for measuring magnetic resistance, is provided between the base layer and the lower ferromagnetic layer. Linear magnetoresistive element. Further, it has a cap layer for surface protection laminated on the upper ferromagnetic layer, and also has a cap layer for surface protection.
The surface according to any one of claims 1 to 9 , wherein the cap layer is made of at least one kind of metal or alloy selected from the group consisting of Ag, Al, Cu, Au, Ru and Pt. Linear magnetoresistive element. Further, it has a pinning layer provided above or below the upper ferromagnetic layer, and also has a pinning layer.
The pinning layer IrMn alloy, the orthogonal direction magnetoresistive element according to any one of claims 1 to 1 0, characterized in that a layer of antiferromagnetic material such as PtMn alloy. A surface orthogonal reluctance (CPPGMR) element having a structure in which a spacer layer is arranged between thin films of Heusler alloy.
The Whistler alloy thin film is composed of a Whistler ferromagnetic alloy having at least one of a B2 regular structure and an L2 ₁ regular structure, and the Whistler ferromagnetic alloy is Co ₂ Fe (Ga _x Ge _1-x ) (0.25 <x). <0.6), Co ₂ FeAl _1-x Si _x (0.0 ≦ x ≦ 1.0), Co ₂ Fe _1-x Mn _x Si (0.0 ≦ x ≦ 1.0), or Co ₂ A Whistler ferromagnetic alloy selected from Fe _1-x Mn _x Ge (0.0 ≦ x ≦ 1.0).
Together with the spacer layer is formed of _{Mg 1-x Ti x O y} (0.5 ≦ x ≦ 1.0,0.8 ≦ y ≦ 1.2) and the conductive non-magnetic metal, surface protection containing nitrogen element A plane perpendicular reluctance (CPPGMR) element, characterized by having no layers . Magnetic head characterized by using a surface direction perpendicular magnetoresistive element according to the orthogonal direction magnetoresistive element or Claim 1 2 according to any one of claims 1 to 11. A magnetic reproduction device according to claim 13 , wherein the magnetic head is used.