JP6907544B2 - Variable heat insulating element, its driving method, and its forming method - Google Patents

Description

The present invention relates to a variable heat insulating element using the spin Seebeck effect and the spin Perche effect, a method for driving the same, and a method for forming the same.

The Perche effect, which generates a heat flow in a certain direction in a material by passing an electric current through a solid material having electrical conductivity, is widely used as a technology for transferring heat and a heat pump technology.

On the other hand, it is also widely known that the Seebeck effect of generating an electric current in a certain direction in a material occurs by passing a heat flow through the same material, that is, by generating a temperature difference at both ends of the material.

In Patent Document 1, by combining these effects, a current is extracted from the Seebeck effect generated in the material in an environment with a temperature difference, and the Pelche effect is caused by the current, so that the apparent thermal resistance of the material changes. An energy-recycling thermal control system is disclosed.

Specifically, Patent Document 1 is a cooling system including a motor and a brake for braking, and at least using a variable thermal resistance for cooling the motor. A perche element whose thermal resistance changes according to the energized state is arranged in a heat transfer path that mediates heat transfer between the motor and the brake. When the brake is hotter than the motor, the thermal resistance of the Pelche element is increased to block the heat transfer from the brake to the motor to avoid overheating and deterioration of the performance of the motor. On the contrary, when the temperature of the motor is higher than that of the brake, the thermal resistance of the Pelche element is reduced to promote heat transfer from the motor to the brake to cool the motor, and the temperature of the brake is quickly raised by the heat of the motor. The braking performance is ensured. The Pelche element is an N-type semiconductor and a P-type semiconductor connected in a π-type by electrodes.

Further, in recent years, the spin Seebeck effect, which is a thermoelectric effect utilizing electron spin in a solid, and the spin Perche effect, which is the opposite effect, are disclosed in Non-Patent Document 1 and Non-Patent Document 2, respectively. According to Non-Patent Document 1, _{when a temperature gradient is applied to the magnetic insulator LaY 2} Fe ₅ O ₁₂ , the heat flow is converted into a spin pressure by the spin Seebeck effect, and the Pt formed on the magnetic insulator converts the spin pressure into a voltage. It is stated that it should be done. Further, Non-Patent Document 2 describes that a spin perche effect is generated in which a heat flow is generated by a spin flow flowing through the interface between _{the ferrimagnetic insulator YIG (Y 3} Fe ₅ O _{12) and Pt.}

JP-A-2010-178466

Uchida et al. , "Spin Seebeck Insulator", Nature Materials, 2010, vol. 9, p. 894. Flipse et al. , "Observaion of the Spin Peltier Effect for Magnetic Insulator", Physical Review Letters, 2014, vol. 113, p. 027601.

Since the Pelche element is used in Patent Document 1, it is necessary to connect the N-type semiconductor and the P-type semiconductor in a π-type by electrodes, which complicates the structure. A spin-perche element that utilizes the spin-perche effect is expected to have a simple structure, is hard to break, and can be manufactured at a lower cost than a perche element. However, it is significantly inferior in the effective efficiency of thermoelectric conversion. Further, a spin Seebeck element that exhibits the spin Seebeck effect, which is the opposite effect of the spin Perche effect, is expected to have a simpler structure, is hard to break, and can be manufactured at a lower cost than a Seebeck element that exhibits the Seebeck effect. .. However, this is also significantly inferior in terms of the effective efficiency of thermoelectric conversion.

Therefore, a variable heat insulating element using the spin Perche effect and the spin Seebeck effect has not been put into practical use. An object of the present invention is to solve this problem and to provide a variable heat insulating element using a spin Perche effect and a spin Seebeck effect.

The present invention has a magnetic film having internal magnetization in at least one direction, a first conductive film magnetically bonded to the magnetic film on one surface of the magnetic film, and the other surface of the magnetic film. Is provided with a second conductive film magnetically bonded to the magnetic film.
Both the first and second conductive films contain at least a part of a material having a spin-orbit interaction, have a spin Hall angle related to the magnitude of the spin-orbit interaction, and the spin-hole angles are mutual. It is a variable heat insulating element having a different reference numeral, wherein the first conductive film, the second conductive film, and a control mechanism capable of changing the electrical conductance can form a closed circuit. ..

Further, in the present invention, the thermal resistance of the variable heat insulating element is increased by short-circuiting the control mechanism of the variable heat insulating element, or the thermal resistance of the variable heat insulating element is opened. Is a method for driving a variable heat insulating element, which is characterized in that the temperature is lower than the short-circuited state.

Further, the present invention forms a first conductive film on the support, which includes a material having a spin-orbit interaction at least in part and has a first spin-hole angle related to the magnitude of the spin-orbit interaction. , A magnetic film having internal magnetization in at least one direction and magnetically bonded to the first conductive film is formed on the first conductive film, and spin-orbit couplings are formed on the magnetic film at least partially. A second spin-hole angle that includes a material having an action, is related to the magnitude of spin-orbit interaction, has a second spin-hole angle having a code different from that of the first spin-hole angle, and is magnetically bonded to the magnetic film. Form a second conductive film,
A method for forming a variable heat insulating element, which comprises connecting to the first conductive film and the second conductive film.

According to the present invention, a variable heat insulating element using the spin Pelche effect and the spin Seebeck effect can be obtained.

Further, in the method for forming a variable heat insulating element of the present invention, batch production can be performed by applying a simple coating process or the like to a part or all of the elements, and the manufacturing cost can be greatly reduced.

It is sectional drawing which shows typically the structure of the variable insulation element which concerns on 1st Embodiment of this invention. It is a top view which shows typically the manufacturing procedure of the variable insulation element which concerns on Example 1 of this invention. It is a top view which shows typically the manufacturing procedure of the variable insulation element which concerns on Example 1 of this invention. It is a top view which shows typically the manufacturing procedure of the variable insulation element which concerns on Example 1 of this invention. It is sectional drawing which shows typically the structure of the variable insulation element which concerns on 2nd Embodiment of this invention. It is sectional drawing which shows typically the structure of the variable insulation element which concerns on 3rd Embodiment of this invention. It is sectional drawing which shows typically the structure of the variable insulation element which concerns on 4th Embodiment of this invention.

Hereinafter, the variable heat insulating element and the manufacturing method thereof according to the embodiment of the present invention will be described in detail with reference to the drawings. However, although the embodiments described below have technically preferable limitations for carrying out the present invention, the scope of the invention is not limited to the following.
(First Embodiment)
<Structure of variable insulation element>
First, the structure of the variable heat insulating element of the first embodiment will be described with reference to FIG.

FIG. 1 is a cross-sectional view schematically showing the structure of the variable heat insulating element of the present embodiment. The variable heat insulating element of the present embodiment has a magnetic film 101 having a constant holding force and internal magnetization. The first conductive film 102 is formed on one surface (upper surface in the figure) of the magnetic film 101. A second conductive film 103 is formed on the other surface (lower surface in the figure) of the magnetic film 101. Both the first conductive film 102 and the second conductive film 103 have a rectangular planar shape.

Contact pads 104, 105, and 106 are formed on both ends of the first conductive film 102 and the second conductive film 103 by using a patterning technique such as screen printing. Further, the first conductive film 102 and the second conductive film 103 are electrically connected by the pad 105. Further, the pads 104 and 106 are connected to the control mechanism 107, respectively.
<Materials and functions that make up each element>
The magnetic film 101 is formed of a material that exhibits a spin Seebeck effect. That is, the magnetic film 101 internally generates _{spin currents J S0} and J _S1 in proportion to the input of the _{heat flow Q 0.}

The magnetic film 101 has magnetism such as ferromagnetism, ferrimagnetism, and antiferromagnetism, and is magnetized in at least one direction except for specific conditions such as the Néel temperature peculiar to magnetic materials and the temperature range above the Curie temperature. Have. In this embodiment, it is magnetized in the direction perpendicular to the paper surface of FIG. The material is preferably an insulator or a material having high insulating properties.

For example, in the case of a magnetic insulator, yttrium iron garnet (YIG, Y ₃ Fe ₅ O ₁₂ ), bismuth (Bi) -doped BiY ₂ Fe ₅ O ₁₂ , and lantern (La) -added LaY ₂ Fe ₅ O _{12 R x} Y _3-x Fe ₅ O ₁₂ in which a part of Y is replaced by an element R having f electrons, and _{M x} Y ₃ Fe _5-x O ₁₂ in which a part of Fe is replaced by a transition metal element M. Can be mentioned. Examples thereof include magnetite (Fe ₃ O ₄ ) and a spinel ferrite material having a composition of MFe ₂ O ₄ (M is a metal element and contains one or more of Fe, Ni, Zn, and Co).

If it is a magnetic semiconductor, it is selected from Fe, Co, and Ni having _{a composition of CuMO 2} or SrMO ₃ (M is a metal element and contains any of Mn, Ni, Co, and Fe) and Fe ₃ O _4. Examples thereof include magnetic oxides (magnetic oxide semiconductors) having semiconductor properties including at least one of them. From the viewpoint of suppressing heat conduction by electrons, it is desirable to use an insulator or a semiconductor.

For the first conductive film 102, it is preferable to use a conductor that exhibits the reverse spin Hall effect or spin-orbit interaction. The magnitude of the inverse spin Hall effect is defined by spin Hall conductivity / electrical conductivity, and can be effectively expressed by a material-specific value called the spin Hall angle, which is between -1 and +1.

In the variable heat insulating element of the present embodiment, a thermal spin current that flows from the higher temperature side to the lower temperature side is generated along the temperature gradient in the magnetic film 101, and further undergoes a process called spin injection, and finally the conductive film. There is an influx of spin angular momentum into.

In spin injection, spins that age-shift around the magnetization direction in the magnetic film 101 near the interface of the conductive film 102 interact with conduction electrons in the conductive film 102 to transfer or receive spin angular momentum. It is a phenomenon.

As a result, conduction electrons having spin move near the spin injection interface in the conduction film 102, and a pure spin current is generated. In this pure spin current, conduction electrons having upspin and downspin flow in the same amount in opposite directions. As a result, there is no charge transfer, but both spins are added because both the sign and the direction of movement are different from each other, and as a result, only the spin angular momentum flows.

Then, this pure spin current is converted into an electric current by the reverse spin Hall effect.

In the present specification, it is expressed that the states in which this spin injection phenomenon can occur are magnetically coupled. This spin injection phenomenon occurs when the magnetic film 101 and the conductive film 102 are in direct contact with each other, or when the spin angular momentum is close enough to be transmitted even if the magnetic film 101 and the conductive film 102 are not in direct contact with each other. .. That is, if there is a gap between the magnetic film 101 and the conductive film 102, or if the spin injection phenomenon can occur even when the intermediate layer is inserted, it is considered that there is a magnetic bond.

That is, the first conductive film 102 is magnetically coupled to the magnetic film 101, spin current J _S0 generated by the spin Seebeck effect beyond the surface flows into the conduction side, the electromotive force generated by inverse spin Hall effect A corresponding thermoelectromotive force E ₀ is generated.

The spin current-to-current conversion efficiency is greater for materials with a large reverse spin Hall effect. For example, a transition metal such as Au, Pt, Pd, or Bi having a relatively large reverse spin Hall effect, a transition metal having a d orbital or an f orbital, or an alloy material containing them is used. Further, the same effect can be obtained only by doping a general metal film material such as Cu with a material such as Fe or Ir in an amount of about 0.5 to 10 mol%.

It is also effective to use a magnetic material as the conductive film 102. In this case, a magnetic-induced thermoelectric effect called the anomalous Nernst effect occurs. The direction of the electromotive force due to the anomalous Nernst effect is the same as or antiparallel to the inverse spin Hall effect, depending on the sign of the anomalous Nernst coefficient.

Usually, it is preferable to use a material in which the electromotive force directions of both effects are in the same direction. However, even if the signs of both effects are different, it is appropriate to use a material in which the _{thermoelectromotive force E 0 that appears as a result of overlapping is large.}

Further, the conductive film 102 includes an oxide conductor such as ITO (Indium Tin Oxide) and compositions CuMO ₂ and SrMO ₃ (M is a metal element and contains any of Mn, Ni, Co, and Fe). It may be a magnetic oxide semiconductor such as.

As the second conductive film 103, a conductor that exhibits the reverse spin Hall effect or spin-orbit interaction can be used as in the material used for the above-mentioned conductive film 102. However, it is preferable to use a conductor material having a spin Hall angle having a code different from that of the first conductive film 102. In the second conductive film 103, a spin current flows out from the second conductive film 103 to the magnetic film 101 side beyond the interface so as to compensate for _{the spin current J S1 generated by the spin Seebeck effect in the magnetic film 101, resulting in reverse.} in order to generate a thermoelectromotive force E ₁ by the spin Hall effect.

For example, when a material mainly containing a metal such as Pt, Pd, or Ni is used for the first conductive film 102, W, Ta, Mo, Nb, Cr, among the transition metals, are used for the second conductive film 103. When V and Ti are used, it is possible to obtain a voltage having a sign opposite to that of Pt, Pd, Ni, and an alloy containing these, which are used for the first conductive film 102. That is, the directions of the currents generated by the reverse spin Hall effect are opposite.

Further, similarly to the first conductive film 102, an alloy material in which impurities are added to the base metal or a magnetic material can be used for the second conductive film 103.

For the pads 104, 105, 106, a material having high electrical conductivity can be used. Further, the pads 104, 105 and 106 may be made of a single material, or a composite material may be used. Further, it is also possible to design the first conductive film 102 and a part of the second conductive film 103 to carry a part or all of the functions of the pads 104, 105 and 106.

For example, in order to improve the adhesion to the magnetic film 101, the first conductive film 102, and the second conductive film 103, a material having high adhesion is used at the interface with each material, and other materials having high conductivity are used. Can be used. Further, in order to protect the surface, the entire surface can be covered with a chemically stable material or a material having excellent wear resistance.

The control mechanism 107 has a mechanism that is connected to the pads 104 and 106 and controls the amount of current flowing between the pads 104 and 106 by reflecting some external factor.

For example, a switch that can switch between short circuit and open can be used by external control.

Further, as the control mechanism 107, an element such as a bimorph switch that can spontaneously change the opening and shorting depending on the environmental temperature can be used. In this case, it is possible to realize an element in which the release and the short circuit are switched near the temperature set as the threshold value without external control.

Further, an element such as a PTC (Positive Temperature Coefficient) thermistor or an NTC (Negative Temperature Coefficient) thermistor, which can spontaneously change the electrical conductance depending on the environmental temperature, can be used. In this case, it is possible to realize an element in which the heat insulating effect changes depending on the temperature near the reference temperature without external control.

Further, by using a sensor that measures not only temperature but also environmental conditions such as external light, sound, and humidity, it is possible to realize an element that operates by reflecting external environmental information.

Further, when a diode having a current rectifying function or the like is used, it is possible to realize an element in which the effect of variable heat insulation can be obtained only when the heat flow flows in one direction.

Further, the control mechanism 107 is provided with measuring elements such as a temperature sensor, a current sensor, a voltage sensor, and a magnetic sensor for grasping the state of the entire element, and the information can be reflected in the operation of the control mechanism. It is also possible to operate the element by taking in a current from an external current source according to the state of the entire element.

From the above elements, a closed circuit is configured in which the first conductive film 102 and the second conductive film 103 are connected in series via the control mechanism 107.

Assuming that the control mechanism 107 is short-circuited, a thermoelectromotive force E ₀ + E _{1 proportional to the heat flow input Q 0} is generated. Further, a current I determined by the impedance Z of the entire closed circuit including the control mechanism 107 flows through the closed circuit.

The current I generates a heat flow by thermoelectric conversion by the spin Perche effect, which is the opposite effect of the spin Seebeck effect.

That is, a spin current is generated in the first conductive film 102 due to the current I due to the spin Hall effect, and a component J _sA flowing into the magnetic film 101 is generated. Furthermore _{J sA} is produce heat flow _{Q A} by spin Peltier effect. Further, in the second conductive film 103, a spin current component J _sB flowing out from the magnetic film 101 is generated, and a heat flow Q _{B due to J sB} is generated.
That is, when the impedance of the control mechanism 107 is almost equal to zero, _{both the heat flows Q A} and Q _B are maximized, and the effective thermal resistance of the element is increased. When impedance such as by the state of opening the control mechanism 107 conversely large infinity, Q _A, Q _B disappears, element is in a state of having a material inherent thermal resistance. Due to the thermoelectric effect utilizing the temperature difference applied to the element, the thermal resistance of the element can be made larger than the thermal resistance of the material itself constituting the element, and the heat insulating performance can be improved. When it is desired to suppress heat insulation performance and dissipate heat, it is possible to suppress an increase in thermal resistance. In addition, the increase or decrease in thermal resistance can be appropriately controlled.

As described above, in the variable heat insulating element according to the present embodiment, since the conductive film covers both sides of the magnetic film as compared with the existing elements using the spin Seebeck and spin Pelche effects, it covers only one side. A simple calculation yields about twice as much thermoelectromotive force as in the case of. Therefore, it is possible to provide a variable heat insulating element using the spin Pelche effect and the spin Seebeck effect. Moreover, the structure is simple because the conductive film only covers both sides of the magnetic film.

Further, in the present embodiment, since two types of conductive films that generate thermoelectromotive forces having different codes are used, it is possible to more easily realize an element structure in which the respective conductive films are electrically connected, and to reduce the manufacturing cost. can.

<Method of forming variable adiabatic element>
Next, a method of forming the variable heat insulating element of the present embodiment will be described with reference to FIGS. 2 to 4.

The variable heat insulating element of the present embodiment is formed on the support 200.

First, a first conductive film 202 is formed on the support 200 so as to have a planar shape in which a part of a rectangle protrudes as shown in FIG. This protruding portion becomes the pad 206. Examples of the film forming method include a method of forming a film by any one of a sputtering method, a vapor deposition method, a plating method, a screen printing method, an inkjet method, a spray method and a spin coating method. Further, coating / sintering of a nanocolloidal solution or the like can be used.

An industrially used patterning method can be applied to the method of forming the shape shown in FIG. Examples include a stencil method, a direct drawing method, a lithography method, and a mask etching method.

Subsequently, the magnetic film 201 is formed as shown in the planar shape shown in FIG. 3 by using the above patterning method or the like. The magnetic film 201 largely overlaps with the first conductive film 202 in a plan view, but the above-mentioned protruding portion of the first conductive film 202 and the opposite end portion do not overlap. This opposite end is another pad.

Examples of the method for forming the magnetic film 201 include a sputtering method, an organic metal decomposition method (MOD (Metal Organic Decomposition) method), a sol-gel method, an aerosol deposition method (AD (Aerosol Deposition) method), a ferrite plating method, and a liquid phase epitaxy method. , Solid phase epitaxy method, vapor phase epitaxy method, dip method, spray method, spin coating method, printing method and the like.

Further, the second conductive film 203 is formed into a film having the shape shown in FIG. 4, that is, the first conductive film 202 having a left-right inverted planar shape by using the same method as the magnetic film 201.

Finally, a variable heat insulating element can be obtained by connecting the control mechanism 207 to the conductive film 202 and the conductive film 203.

In the method of the present embodiment, batch production can be performed by applying a simple coating process or the like to a part or all of the elements, and the manufacturing cost can be greatly reduced. It is also possible to apply a thin film sheet type element over a wide area, and it has a degree of freedom in shape. If the support 200 is made thin, it can be mounted not only on a flat surface but also on a curved surface or a surface having a complicated shape.

The portion of the pad 104 described with reference to FIG. 1 is covered by a portion of the conductive film 202 that does not overlap with the magnetic film 201 or the conductive film 203 (pad 204 of FIG. 4). Further, the portion of the pad 105 in FIG. 1 is covered by a portion (pad 205 in FIG. 4) in which the conductive film 202 and the conductive film 203 directly overlap each other. Further, the portion of the pad 106 is borne by a portion of the conductive film 203 that does not overlap with the magnetic film 201 or the conductive film 202 (pad 206 in FIG. 4).

Hereinafter, the first embodiment will be described in more detail with reference to Examples.
(Example 1)
As a specific example of this embodiment, Example 1 will be described with reference to FIGS. 2 to 4.

First, a polyimide film having a size of 10 cm × 10 cm and a thickness of 25 μm was prepared as the support 200.

Subsequently, using the magnetron sputtering method, W was deposited on the support 200 as the first conductive film 202, and a thickness of 5 nm was deposited on the support 200 using a stencil mask to a size of about 8 cm in width and 8 cm in length.

_{Next, using a known ferrite thin film manufacturing method, a Ni 0.1} Zn _0.1 Fe _1.8 O ₄ film was produced as the magnetic film 101 used for the variable heat insulating element of FIG. The size of the magnetic film was approximately 9 cm in width × 6 cm in length, and the film thickness was 1 um.

Further, using the magnetron sputtering method, Pt was deposited as the second conductive film 203 using a stencil mask to have a size of about 8 cm in width × 8 cm in length and a thickness of 5 nm.

Finally, a relay that can be turned on and off from the outside is connected as the control mechanism 207, and the variable heat insulating element of the present embodiment is manufactured.

When this variable heat insulating element is sandwiched between a reference heat bath whose temperature is an ambient temperature of 23 degrees Celsius and a heat bath on the high temperature side of 53 degrees Celsius, the interfacial thermal resistance between the element and each heat bath and the support Considering the thermal resistance of the variable heat insulating element itself, consider a situation in which a temperature difference of about 1 [mK] is stably generated.

When the control mechanism 207 is in the open state, heat flows through the magnetic film 201, which occupies most of the thickness of the element, with ^{a heat flux density of about 10 [kW / m 2} ], and the thermal resistance θ ₀ is about 0.1. It becomes [μK / (W / m ² )].

When the control mechanism 207 is short-circuited, the effective thermal resistance θ _{1 is the equation θ 1} = 1 [mK] / (10 [MW / m ² ] + Q) obtained by adding the spin Pelche heat flow component to the Fourier relational expression. It can be represented by _A + Q _B). At this time, both _{Q A} and Q _B have the opposite sign to _{Q 0 , so θ 1} is larger than _{θ 0.}

That is, the thermal resistance of the variable heat insulating element can be set to a high state or a low state by operating a switch composed of a relay.
(Second embodiment)
A second embodiment will be described with reference to the cross-sectional view of FIG.

The variable heat insulating element of the present embodiment is covered with an insulating protective film so that the support according to the first embodiment is made of a material having electrical conductivity or the conductive film of the variable heat insulating element is not exposed on the surface. The purpose is to respond when it is necessary to do so.

That is, in addition to the variable heat insulating element of Example 1, a coating layer for insulation and protection is provided, and by using a magnetic insulator for the coating layer, it is larger due to the additional spin perche effect. It is characterized by obtaining a variable heat insulation effect.

As shown in FIG. 5, the variable heat insulating element of the present embodiment includes a support 500 having electrical conductivity, a magnetic film 501 similar to that of the first embodiment, a first conductive film 502, a second conductive film 503, and a control. The mechanism 507 includes a switch capable of external ON / OFF control.

Further, a protective magnetic film 508 is provided between the variable heat insulating element and the support 500, and a protective magnetic film 509 is provided on the surface of the variable heat insulating element. The two protective magnetic films use the same ferrite film as the magnetic film 501 as a material.

As a result, the current generated by the spin Seebeck effect can effectively contribute to the generation of heat flux by the spin Perche effect without being dissipated from the first and second conductive films to the outside of the device, which is effective. Is.

Further, when the protective magnetic film is made of a material having magnetism similar to that of the magnetic film 501 and realizing the propagation of the thermal spin current, the current component of thermoelectric current due to the spin current from both protective magnetic films is added. It is more effective.
(Third Embodiment)
In the third embodiment, an example in which the variable heat insulating element described in the first and second embodiments and the first embodiment is used as the shielding material will be described.

For example, the shield material that covers the aircraft for the purpose of keeping the internal temperature of artificial satellites and space probes constant is to minimize the inflow of radiant heat from the sun and the outflow of radiant heat from the shaded part of the sun. , It is generally preferable to increase the thermal resistance of the material. On the contrary, when operating a device that generates a large amount of heat inside the shield, it is preferable to reduce the thermal resistance and promote heat dissipation. If you want to increase the thermal resistance, short-circuit the variable heat insulating element, and conversely, if you want to reduce the thermal resistance, open it. For that purpose, for example, by using the above-mentioned bimorph switch, PTC thermistor, NTC thermistor or the like as a control mechanism, it is sufficient to automatically switch between opening and shorting depending on the environmental temperature.

In such a case, the variable heat insulating element can provide a thermal resistance change function by a solid element, which is difficult to realize with ordinary materials. Especially, when the spin Seebeck and spin perche effects are used, a thin film or sheet-like element is used. Taking advantage of its shape, it can be easily mounted on a shield material.

Further, the variable heat insulating element described in the second embodiment has a multilayer structure composed of a magnetic film and a conductive film.

As shown in FIG. 6, a first magnetic film 601, a second magnetic film 602, a third magnetic film 603, and further Example 1 formed of the same material as in Example 1 on the support 600, respectively. The first conductive material 604 similar to that of the first magnetic material and the second conductive material 605 having a spin Hall angle having a different code from that of the first magnetic material form a laminated structure as shown in FIG.

At this time, there are films made of different conductive materials on the upper surface and the lower surface of each magnetic film. That is, the first conductive material 604 and the second conductive material 605 are alternately present in the stacking direction and are alternately connected to each other. The parts that are connected alternately are staggered when viewed from above the element so that they do not overlap.

Further, the conductive material forms a closed circuit with an external control mechanism 607. Further, the entire element is covered with a protective magnetic film 606 to maintain insulation.

The laminated structure formed of a plurality of magnetic materials and conductive materials also functions as a light reflection film and an antireflection film according to the period, the combination of materials, and the like. The reflective film functions as a transmission prevention film for light penetrating the film.

That is, as a shield material used for artificial satellites and space probes, the refractive index and film thickness of each material used for the variable heat insulating element are optimized in order to suppress heat inflow due to the solar spectrum having a peak at a wavelength of about 500 nm. It is advisable to design it so that the reflection efficiency is high.
(Fourth Embodiment)
The present embodiment will be described with reference to the cross-sectional view of FIG. In this embodiment, an external power supply 710 is connected in series to the control mechanism 707 of the variable heat insulating element having a laminated structure formed of a plurality of magnetic materials and conductive materials described in the third embodiment.

The shield material that covers the body of the artificial satellite or space probe described in the second embodiment preferably maximizes the heat dissipation efficiency when operating a device that generates a large amount of heat inside the shield.

In this case, not only the change in heat insulation performance due to the energy generated inside the element due to the spin Seebeck effect, but also the external power supply 710 is connected to the multilayer variable heat insulation element 701 as shown in FIG. It can dissipate heat.

A current is passed through the multilayer variable heat insulating element 701 by the external power supply 710. If the side with the control mechanism of the external power supply 710 is + and the opposite side is-, the current flows from the upper conductive film to the lower conductive film, and so on, and returns to the external power supply 710 from the lowermost conductive film. .. The control mechanism is short-circuited. A protective resistor may be inserted.

When an electric current is passed, a spin current is generated in the magnetic film sandwiched between the conductive films due to the spin Hall effect, and as a result, a heat flow (temperature gradient) is generated. That is, a temperature gradient is generated in the film thickness direction of the multilayer variable heat insulating element 701 by the reverse process described in FIG. When the high temperature side of the temperature gradient is brought into contact with a place where heat is desired to be dissipated, for example, the surface of the electronic device, heat can be dissipated from the electronic device. Since the magnitude of the spin current, that is, the magnitude of the temperature gradient can be adjusted by adjusting the current flowing from the external power source 710, the heat insulating performance can be adjusted.

The variable heat insulating element is not limited to the multilayer type, and a single layer type variable heat insulating element as shown in FIG. 1 may be used. Some or all of the above embodiments may also be described, but not limited to:
(Appendix 1)
A first conductive film having a magnetic film having internal magnetization in at least one direction and magnetically bonded to the magnetic film on one surface of the magnetic film, and the magnetic film on the other surface of the magnetic film. With a second conductive film that is magnetically coupled to
Both the first and second conductive films contain at least a part of a material having a spin-orbit interaction, have a spin Hall angle related to the magnitude of the spin-orbit interaction, and the spin-hole angles are mutually exclusive. A variable heat insulating element having a different reference numeral, wherein the first conductive film, the second conductive film, and a control mechanism capable of changing the electrical conductance can form a closed circuit.
(Appendix 2)
The variable heat insulating element according to Appendix 1, wherein the first conductive film, the second conductive film, and the control mechanism form a closed circuit in series.
(Appendix 3)
The variable heat insulating element according to Appendix 1 or 2, wherein the first and second conductive films are electrically connected at one end.
(Appendix 4)
The variable heat insulating element according to any one of Supplementary note 1 to 3, wherein the magnetic film is an insulator or a semiconductor.
(Appendix 5)
The variable heat insulating element according to any one of Supplementary note 1 to 4, wherein the first and second conductive films are magnetic films.
(Appendix 6)
The variable heat insulating element according to any one of Supplementary note 1 to 5, wherein the first conductive film, the second conductive film, the control mechanism, and the power supply form a closed circuit in series.
(Appendix 7)
The variable heat insulating element according to any one of Supplementary note 1 to 6, which has an insulating protective film covering the first conductor and the second conductor.
(Appendix 8)
The variable heat insulating element according to Appendix 7, wherein the insulating protective film is a magnetic film having internal magnetization in at least one direction and is magnetically bonded to the first conductor and the second conductor.
(Appendix 9)
The variable heat insulating element according to any one of Appendix 1 to 8, wherein a plurality of the first conductive film, the magnetic film, and the second conductive film are laminated.
(Appendix 10)
Any one of the items 7 to 9 in which at least one of the magnetic film, the first conductive film, the second conductive film, and the protective film functions as a transmission prevention film with respect to light penetrating the film. The variable insulation element described in.
(Appendix 11)
The variable heat insulating element according to any one of Appendix 1 to 10, wherein the variable heat insulating element is formed on a sheet-shaped support.
(Appendix 12)
The variable heat insulating element according to any one of Appendix 1 to 11, wherein the control mechanism is a switch capable of switching between open and short circuits.
(Appendix 13)
The variable heat insulating element according to Appendix 12, wherein as the switch, a switch that switches between open and short circuits according to temperature is used.
(Appendix 14)
The variable heat insulating element according to any one of Supplementary note 1 to 11, wherein a rectifying element is provided as the control mechanism, and when a heat flow flows in a certain direction, the thermal resistance of the variable heat insulating element is increased.
(Appendix 15)
By short-circuiting the control mechanism of the variable heat insulating element according to any one of Appendix 1 to 14, the thermal resistance of the variable heat insulating element is increased, or by opening the control mechanism. A method for driving a variable heat insulating element, which comprises setting the thermal resistance to a state lower than the short-circuited state.
(Appendix 16)
The method for driving a variable heat insulating element according to Appendix 15, wherein the state in which the thermal resistance of the variable heat insulating element is high is a state in which the thermal resistance is higher than the thermal resistance of the material constituting the variable heat insulating element.
(Appendix 17)
The method for driving a variable heat insulating element according to any one of Appendix 6 to 16, wherein the high temperature side of the temperature gradient generated by the current flowing from the power supply to the closed circuit in series is brought into contact with a portion to be dissipated. How to drive the heat insulating element.
(Appendix 18)
A first conductive film containing a material having spin-orbit interaction at least in part and having a first spin-hole angle related to the magnitude of spin-orbit interaction is formed on the support, and the first conductive film is formed. A material having internal magnetization in at least one direction, forming a magnetic film magnetically bonded to the first conductive film on the conductive film, and having spin-orbit interaction at least partially on the magnetic film. A second conductive film that includes, has a second spin-hole angle of a code different from that of the first spin-hole angle, and is magnetically coupled to the magnetic film, is related to the magnitude of spin-orbit interaction. Form and
A method for forming a variable heat insulating element, which comprises connecting to the first conductive film and the second conductive film.

101, 201, 501 Magnetic film 102, 202, 502 First conductive film 103, 203, 503 Second conductive film 104, 105, 106, 205 Pad 107, 207, 507, 607, 707 Control mechanism 200, 500, 600 Support 508, 509, 606 Protective magnetic film 601 First magnetic film 602 Second magnetic film 603 Third magnetic film 604 First conductive material 605 Second conductive material 701 Multi-layer variable insulation element 710 External power supply

Claims (11)

A first conductive film having a magnetic film having internal magnetization in at least one direction and magnetically bonded to the magnetic film on one surface of the magnetic film, and the magnetic film on the other surface of the magnetic film. With a second conductive film that is magnetically coupled to
Both the first and second conductive films contain at least a part of a material having a spin-orbit interaction, have a spin Hall angle related to the magnitude of the spin-orbit interaction, and the spin-hole angles are mutual. to a different code,
The first conductive film, the second conductive film, a control mechanism capable of changing the electrical conductance, and a variable heat insulating element in which a power source constitutes a closed circuit in series. The variable heat insulating element according to claim 1, wherein the first and second conductive films are electrically connected at one end. The variable heat insulating element according to claim 1 or 2 , further comprising an insulating protective film covering the first conductive film and the second conductive film. The variable heat insulating element according to claim 3 , wherein the insulating protective film is a magnetic film having internal magnetization in at least one direction and is magnetically bonded to the first conductive film and the second conductive film. The variable heat insulating element according to any one of claims 1 to 4 , wherein a plurality of the first conductive film, the magnetic film, and the second conductive film are laminated. The thermal resistance of the variable heat insulating element is set to a high state by short-circuiting the control mechanism of the variable heat insulating element according to any one of claims 1 to 5, or the control mechanism is set to an open state. A method for driving a variable heat insulating element, which comprises setting the thermal resistance to a state lower than that of the short-circuited state. The method for driving a variable heat insulating element according to any one of claims 1 to 5 , wherein the high temperature side of the temperature gradient generated by the current flowing from the power source to the closed circuit in series is brought into contact with a portion to be dissipated. How to drive a variable insulation element. A first conductive film containing a material having spin-orbit interaction at least in part and having a first spin-hole angle related to the magnitude of spin-orbit interaction is formed on the support, and the first conductive film is formed. A material having internal magnetization in at least one direction, forming a magnetic film magnetically bonded to the first conductive film on the conductive film, and having spin-orbit interaction at least partially on the magnetic film. A second conductive film that includes, has a second spin-hole angle of a code different from that of the first spin-hole angle, and is magnetically coupled to the magnetic film, is related to the magnitude of spin-orbit interaction. Form and
Connecting the first conductive film and the second conductive film,
Formation of a variable heat insulating element characterized by connecting the first conductive film, the second conductive film, a control mechanism capable of changing electrical conductance, and a power supply so as to form a closed circuit in series. Method. A first conductive film having a magnetic film having internal magnetization in at least one direction and magnetically bonded to the magnetic film on one surface of the magnetic film, and the magnetic film on the other surface of the magnetic film. With a second conductive film that is magnetically coupled to
Both the first and second conductive films contain at least a part of a material having a spin-orbit interaction, have a spin Hall angle related to the magnitude of the spin-orbit interaction, and the spin-hole angles are mutually exclusive. A closed circuit can be configured by the first conductive film, the second conductive film, and a control mechanism capable of changing the electrical conductance, which have different symbols.
A variable heat insulating element that covers the first conductive film and the second conductive film and has an insulating protective film having internal magnetization in at least one direction. A first conductive film having a magnetic film having internal magnetization in at least one direction and magnetically bonded to the magnetic film on one surface of the magnetic film, and the magnetic film on the other surface of the magnetic film. With a second conductive film that is magnetically coupled to
Both the first and second conductive films contain at least a part of a material having a spin-orbit interaction, have a spin Hall angle related to the magnitude of the spin-orbit interaction, and the spin-hole angles are mutually exclusive. It has a different code and
A method for driving a variable heat insulating element, wherein the first conductive film, the second conductive film, a control mechanism capable of changing electrical conductance, and a power supply can form a closed circuit in series.
A method for driving a variable heat insulating element in which a high temperature side of a temperature gradient generated by a current flowing from a power source to a closed circuit in series is brought into contact with a portion where heat is desired to be dissipated. A first conductive film having a magnetic film having internal magnetization in at least one direction and magnetically bonded to the magnetic film on one surface of the magnetic film, and the magnetic film on the other surface of the magnetic film. With a second conductive film that is magnetically coupled to
Both the first and second conductive films contain at least a part of a material having a spin-orbit interaction, have a spin Hall angle related to the magnitude of the spin-orbit interaction, and the spin-hole angles are mutually exclusive. It has a different code and
A plurality of the first conductive film, the magnetic film, and the second conductive film are laminated,
A method for driving a variable heat insulating element, wherein the first conductive film, the second conductive film, a control mechanism capable of changing electrical conductance, and a power supply can form a closed circuit in series.
A method for driving a variable heat insulating element in which a high temperature side of a temperature gradient generated by a current flowing from a power source to a closed circuit in series is brought into contact with a portion where heat is desired to be dissipated.

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