JP2019087697A - Thermoelectric converter and heat transport system - Google Patents

Abstract

To improve the performance of a thermoelectric converter.SOLUTION: A thermoelectric conversion device HD1 includes a magnetic material portion MM1, an observation portion OB that observes a change in the magnetization state of the magnetic material portion MM1, a control portion GT that controls the magnetization state of the magnetic material portion MM1, and a conversion portion CV that converts magnetic energy in the magnetic material portion MM1 into electric energy, in which the magnetic material portion MM1 includes a first nonmagnetic layer NM1, a first magnetic layer MG1 formed on the first nonmagnetic layer NM1 and a second nonmagnetic layer NM2 formed on the first magnetic layer MG1 and made of a material different from that of the first nonmagnetic layer NM1, and the film thickness of the first magnetic layer MG1 increases in a first direction of the magnetic material portion MM1.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a thermoelectric conversion device and a heat transport system.

  In recent years, the effective use of heat has attracted attention. In particular, computers and power devices including semiconductor devices generate a lot of heat, and these heats are released without being used, and are therefore called exhaust heat. Despite the high total energy of such waste heat, no effective energy recovery technology has been established.

  Patent Document 1 (Japanese Unexamined Patent Publication No. 2012-185897), for example, describes that heat generated from a semiconductor chip is converted into electrical energy by a thermoelectric conversion element and supplied to a power supply wiring.

JP, 2012-185897, A

  The inventor of the present application is studying conversion of magnetic energy generated by thermal fluctuation into electrical energy in a thermoelectric conversion device. It is desirable to improve the performance of the thermoelectric conversion device by devising the structure of the thermoelectric conversion device.

  Other problems and novel features will be apparent from the description of the present specification and the accompanying drawings.

  The thermoelectric conversion device according to one embodiment includes a magnetic material portion, an observation portion that observes a change in the magnetization state of the magnetic material portion, a control portion that controls the magnetization state of the magnetic material portion, and the inside of the magnetic material portion. And a converter configured to convert magnetic energy into electrical energy. The magnetic material portion is formed on a first nonmagnetic material layer, a first magnetic material layer formed on the first nonmagnetic material layer, and the first nonmagnetic material layer. And a second nonmagnetic layer made of a material different from the layer, and the film thickness of the first magnetic layer becomes thicker toward the first direction.

  According to one embodiment, the performance of the thermoelectric conversion device can be improved.

It is a top view which shows the structure of the thermoelectric conversion apparatus of one Embodiment. It is sectional drawing which shows the structure which cut | disconnected the thermoelectric conversion apparatus of one Embodiment along the AA of FIG. (A) is sectional drawing which shows the structure which cut | disconnected the thermoelectric conversion apparatus of one Embodiment along the BB line of FIG. 1, (b) is a potential figure corresponding to Fig.3 (a). It is a schematic diagram of the skyrmion which generate | occur | produces in the magnetic material part of one Embodiment. (A) is an operation principle figure of the thermoelectric conversion device of one embodiment, (b) is a potential figure corresponding to Drawing 5 (a). (A) is an operation principle diagram of the thermoelectric conversion device following FIG. 5 (a), (b) is a potential diagram corresponding to FIG. 6 (a), (c) is a control unit in FIG. FIG. 5 is a potential diagram showing a state in which a voltage is applied between the electrodes. (A) is an operation principle diagram of the thermoelectric conversion device following FIG. 6 (a), (b) is a potential diagram corresponding to FIG. 7 (a), (c) is a control unit further in FIG. 7 (b) FIG. 7 (d) is a potential diagram showing a state where skirmion has further occurred in FIG. 7 (c), in which a voltage is applied between the electrodes of FIG. It is sectional drawing which shows the structure which cut | disconnected the thermoelectric conversion apparatus of a modification in the position corresponded to the AA of FIG. It is a block diagram of the heat transport system of one embodiment.

  Hereinafter, embodiments of the present invention will be described in detail based on the drawings. In all the drawings for describing the embodiments, members having the same functions are denoted by the same reference numerals, and the repetitive description thereof will be omitted. Further, in the following embodiments, the description of the same or similar parts will not be repeated in principle unless otherwise particularly required.

Embodiment
[About the process of examination]
First, before the embodiment is described, matters considered by the present inventor will be described.

  As described above, no effective energy recovery technology has been established for exhaust heat generated from computers and power devices including semiconductor devices.

  For example, the thing using the Seebeck effect is known for the thermoelectric conversion element used conventionally. The Seebeck effect is an effect in which a temperature difference of an object is directly converted to a voltage. The thermoelectric conversion element using a temperature difference needs to control the temperature difference, has many problems to be considered such as devising a heat dissipation structure, and has not been put to practical use as a highly versatile exhaust heat utilization technology.

  Therefore, as another approach, an attempt may be made to use heat-driven particles or quasi-particles as a carrier of heat and efficiently extract these particles or quasi-particles as electrical energy. If these particles or quasi-particles can be controlled, the temperature difference is not necessary.

  Examples of these particles or quasiparticles include electrons, phonons (lattice vibration) and magnons (spin waves). However, particles or quasiparticles such as electrons, phonons and magnons are difficult to control because they are always randomly moved by heat, and they have not been used as energy generating resources. Specifically, there is a problem that electrons and magnons are too small in size as particles or quasiparticles, making them difficult to observe. In addition, phonons have a problem that control by an electric field or a magnetic field is difficult. Moreover, the size of the magnetic domain, which is a magnetic structure, is too large and interacts with the entire system, and the structure does not change with the energy of the thermal fluctuation level, and is not suitable as a heat carrier. is there.

  From the above, it is desirable to use thermoelectric conversion devices and a heat transport system that recover waste heat as energy using particles or quasi-particles as carriers without any temperature difference.

[About the structure of the thermoelectric converter]
FIG. 1 is a plan view showing the structure of the thermoelectric conversion device HD1 of the present embodiment, and FIG. 2 is a cross section showing the structure of the thermoelectric conversion device HD1 of the present embodiment taken along line A-A of FIG. 3A is a cross-sectional view showing a structure in which the thermoelectric conversion device HD1 of the present embodiment is cut along the line B-B in FIG. 1, and FIG. 3B is a thermoelectric conversion of the present embodiment It is a potential figure corresponding to Drawing 3 (a) of conversion device HD1.

  FIG. 1 shows the top surface of the magnetic material portion MM1 and the top surface of the conversion portion CV, which will be described later, in the thermoelectric conversion device HD1 of the present embodiment, and the observation portion OB and the control portion GT on the magnetic material portion MM1 are also included. It shows. On the other hand, illustration of a wire for connecting to the observation part OB, the control part GT and the conversion part CV, an interlayer insulating film, a contact plug, a pad and the like is omitted. As shown in FIG. 1, the thermoelectric conversion device HD1 of the present embodiment is formed in a substantially rectangular shape in plan view. That is, the magnetic material portion MM1 included in the thermoelectric conversion device HD1 is also formed in a substantially rectangular shape in plan view.

  FIG. 2 shows a structure in which the thermoelectric conversion device HD1 of the present embodiment is cut along the line A-A in FIG. 1, that is, the longitudinal direction of the magnetic material portion MM1. As shown in FIG. 2, the thermoelectric conversion device HD1 of the present embodiment includes a substrate SUB in which an insulating film IL1 is formed on the main surface. The substrate SUB is made of, for example, silicon. The insulating film IL1 is made of, for example, a silicon oxide film, and can be formed by thermal oxidation of silicon constituting the substrate SUB. The substrate SUB has an area AR1 and an area AR2. The area AR1 and the area AR2 correspond to different plane areas of the main surface of the same SUB. In the present embodiment, the magnetic material portion MM1 is formed in the region AR1. Further, an observation unit OB described later and a control unit GT are formed in the area AR1. In the region AR2, a conversion portion CV is formed which converts magnetic energy in the magnetic material portion MM1 into electrical energy. In the region AR1, an insulating film IL2 is formed on the magnetic material portion MM1 so as to cover the observation portion OB and the control portion GT. Similarly, in the region AR2, the insulating film IL2 is formed over the conversion portion CV. The insulating film IL2 is made of, for example, a silicon oxide film.

  First, the structure of the magnetic material portion MM1 of the present embodiment formed in the region AR1 will be described. The magnetic material portion MM1 includes a first nonmagnetic layer NM1, a first magnetic layer MG1 formed on the first nonmagnetic layer NM1, and a second nonmagnetic layer formed on the first magnetic layer MG1. It consists of body layer NM2. The film thickness of the first magnetic material layer MG1 of the present embodiment increases in the longitudinal direction (first direction) of the magnetic material portion MM1.

  The first nonmagnetic layer NM1 is made of a nonmagnetic metal having electrons in the f orbital whose spin orbital interaction is larger than other orbitals (s orbital, p orbital, d orbital), for example, hafnium (Hf), tantalum It consists of (Ta), tungsten (W), rhenium (Re), osmium (Os), iridium (Ir), platinum (Pt) or gold (Au), preferably platinum (Pt) or tantalum (Ta). As described later, the first nonmagnetic layer NM1 doubles as an electrode of the observation unit OB and an electrode of the control unit. The first magnetic layer MG1 is made of a material having strong magnetic exchange interaction, that is, made of a ferromagnetic material, preferably made of a metal such as iron (Fe) or cobalt (Co) or an alloy thereof, more preferably made of CoFeB Become. The second nonmagnetic layer NM2 is made of a nonmagnetic insulator, preferably made of a nonmagnetic metal oxide, and more preferably made of magnesium oxide (MgO).

  Although the first nonmagnetic layer NM1 is made of nonmagnetic metal and the second nonmagnetic layer NM2 is made of nonmagnetic insulator as an example, the present invention is not limited to this. The body layer NM1 and the second nonmagnetic layer NM2 may be made of nonmagnetic materials different from each other. Further, although the magnetic material portion MM1 is formed on the insulating film IL1 in the present embodiment, the present invention is not limited to this.

  The length dimension of the magnetic material portion MM1 is, for example, about 1 μm, and the width dimension of the magnetic material portion MM1 is, for example, about 500 nm. The film thickness of the first nonmagnetic layer NM1 is, for example, about 1 to 10 nm, and preferably about 4.5 nm. The film thickness of the second nonmagnetic layer NM2 is, for example, about 1 to 10 nm, and preferably about 1.4 nm. Further, the film thickness of the first magnetic layer MG1 is about 1 to 2 nm at the thinnest portion and about 10 nm at the thickest portion, and the film thickness of the first magnetic layer MG1 is along the longitudinal direction of the magnetic material portion MM1. It is getting thicker at a certain rate.

  FIG. 3A shows a structure obtained by cutting the thermoelectric conversion device HD1 of the present embodiment along the line B-B in FIG. 1, that is, the width direction. As shown to Fig.3 (a), barrier part BA1 and BA2 are formed in the width direction both ends of 1st magnetic material layer MG1 of this Embodiment. In the widthwise central portion of the first magnetic layer MG1, a skirmion generating portion SP is formed so as to be sandwiched by the barrier portions BA1 and BA2. Note that FIG. 2 described above corresponds to a cross-sectional view of the skillmion generation unit SP cut longitudinally.

  Each of the barrier portions BA1 and BA2 and the skyrmion generation portion SP includes a first nonmagnetic layer NM1, a first magnetic layer MG1 formed on the first nonmagnetic layer NM1, and a first magnetic layer MG1. And a second nonmagnetic layer NM2 formed thereon. However, the film thickness of the first magnetic layer MG1 included in the barrier portions BA1 and BA2 is larger than the film thickness of the first magnetic layer MG1 included in the skyrmion generating portion SP. In the present embodiment, the upper surface of the second nonmagnetic material layer NM2 is included in the skyrmion generation unit SP in order to make the upper surface equal to or the same height as the barrier units BA1 and BA2 and the skyrmion generation unit SP. The film thickness of the second nonmagnetic layer NM2 is larger than the film thickness of the second nonmagnetic layer NM2 included in the barrier portions BA1 and BA2. Then, the sum of the film thickness of the first magnetic layer MG1 included in the skyrmion generation unit SP and the film thickness of the second nonmagnetic layer NM2 included in the skyrmion generation unit SP corresponds to the barrier portions BA1 and BA2. It is the same as the sum of the film thickness of the included first magnetic layer MG1 and the film thickness of the second nonmagnetic layer NM2 included in the barrier portions BA1 and BA2.

  As described above, the film thickness of the first magnetic layer MG1 included in the skyrmion generation part SP is about 1 to 2 nm at the thinnest portion and about 10 nm at the thickest portion. The film thickness of the first magnetic layer MG1 included in the skyrmion generator SP shown in FIG. 3A is about 2 to 3 nm. The film thickness of the first magnetic layer MG1 included in the barrier portions BA1 and BA2 is, for example, about 10 to 20 nm. The length occupied by the skyrmion generating portion SP (the width dimension of the skyrmion generating portion SP) to the width dimension of the magnetic material portion MM1 is, for example, about 10 to 100 nm. The length occupied by the barrier portions BA1 and BA2 (the width dimensions of the barrier portions BA1 and BA2) with respect to the width dimension of the magnetic material portion MM1 is, for example, about 10 to 200 nm.

  A plurality of observation portions OB for observing changes in the magnetization state of the magnetic material portion MM1 and control portions GT for controlling the magnetization state of the magnetic material portion MM1 are alternately provided along the length direction of the magnetic material portion MM1. It is done. It is preferable that the distance between the observation unit OB and the control unit GT be as close as possible without contact. The plurality of observation parts OB provided along the longitudinal direction of the magnetic material part MM1 will be referred to as observation parts OB1, OB2 and OB3 in the order in which the film thickness of the first magnetic layer MG1 present below them increases. Similarly, a plurality of control parts GT provided along the longitudinal direction of the magnetic material part MM1 will be referred to as control parts GT1 and GT2 in the order in which the film thickness of the first magnetic layer MG1 present below them becomes thicker. . The thermoelectric conversion device HD1 of the present embodiment has been described by way of example in which there are three observation units OB and two control units GT, but the number of observation units OB and control units GT is not limited.

  Next, the structure of the observation unit OB of the present embodiment will be described. The observation part OB is formed in a substantially rectangular shape in plan view. The observation part OB includes a first nonmagnetic layer NM1, a first magnetic layer MG1 on the first nonmagnetic layer NM1, a second nonmagnetic layer NM2 on the first magnetic layer MG1, and a second nonmagnetic layer NM2. The second magnetic layer MG2 is formed on the nonmagnetic layer NM2, and the electrode M1 is formed on the second magnetic layer MG2. The second magnetic layer MG2 is made of a ferromagnetic material, and is preferably made of a metal such as iron (Fe) or cobalt (Co) or an alloy thereof. The electrode M1 is made of nonmagnetic metal, preferably platinum (Pt) or tantalum (Ta). The film thickness of the second magnetic layer MG2 is, for example, about 1 to 10 nm, and preferably about 4.5 nm. The film thickness of the electrode M1 is, for example, about 1 to 10 nm, preferably about 4.5 nm. The width dimension of the magnetic material portion MM1 and the length dimension of the observation portion OB (electrode M1) are the same. The length occupied by the observation portion OB (the width dimension of the electrode M1) with respect to the length dimension of the magnetic material portion MM1 is, for example, about 10 to 50 nm.

  The first nonmagnetic material layer NM1, the first magnetic material layer MG1 and the second nonmagnetic material layer NM2 included in the observation part OB are the first nonmagnetic material layer NM1 and the first magnetic material layer included in the magnetic material part MM1. The same as MG1 and the second nonmagnetic layer NM2. Then, the first magnetic layer MG1, the second nonmagnetic layer NM2, and the second magnetic layer MG2 included in the observation part OB constitute an MTJ (Magnetic Tunnel Junction: magnetic tunnel junction) element, and the first nonmagnetic body The layer NM1 and the electrode M1 constitute a pair of electrodes for applying a voltage to the MTJ element.

  Here, the MTJ element is an element having a basic structure of three layers of a magnetic layer, a barrier layer (nonmagnetic insulator layer), and a magnetic layer. By the barrier layer being sandwiched between the two magnetic layers, a magnetic field is applied to the barrier layer. When an electric field is applied to the barrier layer through the two magnetic layers, a tunnel current flows in the barrier layer. Here, the tunnel current flowing in the barrier layer depends on the direction of the magnetic moment of the two magnetic layers. Specifically, when the magnetization directions of the two magnetic layers coincide with each other, the tunnel current flowing through the barrier layer is smaller than that when the magnetization directions of the two magnetic layers do not coincide with each other. That is, when the magnetization directions of the two magnetic layers coincide with each other, the resistance value of the barrier layer is larger than that when the magnetization directions of the two magnetic layers do not coincide with each other. As a result, the magnetization state of the magnetic layer can be observed by the MTJ element forming the observation part OB. The observation part OB of the present embodiment is provided to observe the magnetization state of the first magnetic layer MG1 as described later.

  Although observation part OB of this embodiment explained the case where an MTJ element was included, for example, it is not limited to this, but a giant magnetoresistive element may be included. In this case, ferromagnetic metal layers and nonmagnetic metal layers are alternately stacked on the second nonmagnetic layer. In such a configuration, when a voltage is applied between the laminated magnetic metal layer and the nonmagnetic metal layer, the magnetic metal layer and the nonmagnetic metal layer are not selected according to the magnetization state of the first magnetic layer MG1. The resistance value with the magnetic metal layer changes. As a result, the magnetization state of the magnetic layer can be observed by the MTJ element forming the observation part OB.

  Next, the structure of control unit GT of the present embodiment will be described. The controller GT is formed in a substantially rectangular shape in plan view. The control unit GT includes a first nonmagnetic layer NM1, a first magnetic layer MG1 on the first nonmagnetic layer NM1, a second nonmagnetic layer NM2 on the first magnetic layer MG1, and a second nonmagnetic layer NM2. And an electrode M2 formed on the nonmagnetic layer NM2. The electrode M2 is made of nonmagnetic metal, preferably platinum (Pt) or tantalum (Ta). The film thickness of the electrode M2 is, for example, about 1 to 20 nm, and preferably about 10 nm. The width dimension of the magnetic material portion MM1 and the length dimension of the control portion GT (electrode M2) are the same. The length occupied by the control part GT (the width dimension of the electrode M2) with respect to the length dimension of the magnetic material part MM1 is, for example, about 10 to 50 nm.

  The first nonmagnetic material layer NM1, the first magnetic material layer MG1 and the second nonmagnetic material layer NM2 included in the control unit GT are the first nonmagnetic material layer NM1 and the first magnetic material layer included in the magnetic material part MM1. The same as MG1 and the second nonmagnetic layer NM2. Then, the first nonmagnetic layer NM1 and the electrode M2 included in the control unit GT constitute a pair of electrodes for applying a voltage to the first magnetic layer MG1 and the second nonmagnetic layer NM2.

  Here, when a voltage is applied between the first nonmagnetic layer NM1 and the electrode M2 included in the control unit GT, a voltage is applied to the interface between the first magnetic layer MG1 and the second nonmagnetic layer NM2. Ru. Thereby, the magnetic anisotropy of the interface between the first magnetic layer MG1 and the second nonmagnetic layer NM2 is changed, and the magnetization state of the first magnetic layer MG1 is modulated. As mentioned above, the control part GT of this Embodiment can modulate the magnetization state of 1st magnetic substance layer MG1, and can control the magnetic stability in 1st magnetic substance layer MG1. The magnitude of the voltage applied to the interface between the first magnetic layer MG1 and the second nonmagnetic layer NM2 is, for example, about 10 to 1000 V.

  In particular, by laminating the second nonmagnetic layer NM2 made of MgO on the first magnetic layer MG1 made of CoFeB of about 1 to 2 nm, the first magnetic layer MG1 is directed in a plane perpendicular direction (a first magnetic layer). It has magnetic anisotropy in the thickness direction of MG1. Therefore, when a voltage is applied between the electrodes (between the first nonmagnetic layer NM1 and the electrode M2, hereinafter the same) of the control part GT formed in the upper part in the thickness direction of the first magnetic layer MG1, the first magnetic The magnetization state of the body layer MG1 can be efficiently modulated.

  Although not shown, in the control unit GT, a feedback circuit for performing input and output of signal current with the observation unit OB is formed, and is electrically connected to the observation unit OB. Specifically, the interval between the electrodes of the observation parts OB1, OB2 and OB3 (between the first nonmagnetic layer NM1 and the electrodes M1 of the observation parts OB1, OB2 and OB3, the same applies hereinafter) with a period of about 1 to 50 ns The observation units OB1, OB2, and OB3 are operated by repeating application / non-application of voltage. Thereby, the magnetization state of the first magnetic layer MG1 in the region where the observation parts OB1, OB2, OB3 are formed is observed at intervals of about 1 to 50 ns. The feedback circuit can control the application of a voltage to the control units GT1 and GT2 based on the observation result of the magnetization state of the first magnetic layer MG1 by the observation units OB1, OB2, and OB3.

  Next, the structure of the conversion unit CV of the present embodiment formed in the region AR2 will be described. The conversion part CV consists of an electrode M3. The electrode M3 is made of a nonmagnetic metal having electrons in the f orbital whose spin orbital interaction is larger than other orbitals (s orbital, p orbital, d orbital), for example, hafnium (Hf), tantalum (Ta), tungsten It consists of (W), rhenium (Re), osmium (Os), iridium (Ir), platinum (Pt) or gold (Au), preferably platinum (Pt) or tantalum (Ta). The electrode M3 is formed in a substantially rectangular shape in a plan view, and is in contact with the first magnetic material layer MG1 included in the magnetic material portion MM1 formed in the region AR1 along the longitudinal direction end of the magnetic material portion MM1. ing. In particular, since the film thickness of the first magnetic layer MG1 increases in the longitudinal direction of the magnetic material portion MM1, the conversion portion CV is formed of the end portions in the length direction of the first magnetic layer MG1. It is provided on the side where the film thickness of the first magnetic layer MG1 is the largest.

  The electrode M3 is not in electrical contact with the first nonmagnetic layer NM1 formed in the region AR1. The film thickness of the electrode M3 is preferably the same as the film thickness of the first magnetic layer MG1. The conversion unit CV can convert a magnetic structure (for example, skyrmion to be described later) into a voltage (electromotive force) by the reverse spin Hall effect. Specifically, when the magnetic structure present in the first magnetic layer MG1 contacts the electrode M3, an electromotive force is generated in the electrode M3 in the direction perpendicular to the direction of the magnetic moment of the magnetic structure.

  From the above, the thermoelectric conversion device HD1 of the present embodiment extracts heat as electric energy via magnetic energy by converting the magnetic structure generated in the magnetic material portion MM1 due to thermal fluctuation into an electromotive force by the conversion portion CV. Can.

  In order to use magnetic energy as it is, spin waves are excited by skirmions instead of the conversion part CV, and the spin waves are used for writing or erasing of MRAM (Magnetoresistive Random Access Memory: magnetoresistive memory). It is also possible.

[About the main features and effects]
As shown in FIG. 2, the main features of the thermoelectric conversion device HD1 of the present embodiment are the magnetic material portion MM1, the observation portion OB for observing the change in the magnetization state of the magnetic material portion MM1, and the magnetic material portion MM1. A control unit GT that controls the magnetization state and a conversion unit CV that converts magnetic energy into electrical energy are provided. A plurality of observation parts OB and control parts GT are alternately provided along the longitudinal direction of the magnetic material part MM1. The magnetic material portion MM1 is composed of the first nonmagnetic layer NM1, the first magnetic layer MG1 and the second nonmagnetic layer NM2, and the film thickness of the first magnetic layer MG1 is the length of the magnetic material portion MM1. The thickness increases in the longitudinal direction. The conversion portion CV is provided on the side of the end of the magnetic material portion MM1 in the length direction where the film thickness of the first magnetic layer MG1 is the largest.

  In this embodiment, by adopting such a configuration, exhaust heat can be recovered as energy in the state where there is no temperature difference. The reason will be specifically described below.

  FIG. 4 is a schematic view of skyrmions formed in the magnetic material portion of the present embodiment, and FIGS. 5A, 6A and 7A are operation principle diagrams of the thermoelectric conversion device of the present embodiment. FIGS. 5 (b), 6 (b) and 7 (b) correspond to FIGS. 5 (a), 6 (a) and 7 (a), respectively, in the thermoelectric conversion device of this embodiment. It is a potential diagram. FIG. 6 (c) is a potential diagram showing a state in which a voltage is applied between the electrodes of the control unit in FIG. 6 (b). FIG.7 (c) is a potential figure which shows the state which applied the voltage between the electrodes of a control part in FIG.7 (b). FIG. 7 (d) is a potential diagram showing a state where skirmion has further occurred in FIG. 7 (c).

  As described above, in order to use particles or quasiparticles, which are always randomly moved by heat, as a carrier of heat, the present inventors have developed a skyrmion which is one of the magnetic structures (skyrmion, skyrmion). (It is also called). As shown in FIG. 4, skyrmions are vortex-like magnetic structures having a diameter D of several nanometers to several hundreds of nanometers. Skirmions are known to behave as stable quasiparticles with finite mass in magnetic thin films. The reason why skyrmion is preferable is that (1) the skyrmion has a size that is easy to observe, (2) the skyrmion is generated by energy of the thermal fluctuation level, and is stably present at normal temperature, (3) It can be mentioned that the skyrmion can be easily controlled by an electric field or a magnetic field.

  In order to generate skirmions, a structure in which a magnetic layer (magnetic thin film) is sandwiched by two nonmagnetic layers (nonmagnetic thin films) is required. The magnetic layer should be made of a material having strong magnetic exchange interaction, that is, a ferromagnetic material. Also, the two nonmagnetic layers are made of materials different from each other, and at least one of the nonmagnetic layers is in the f orbital having larger spin orbital interaction than the other orbitals (s orbital, p orbital, d orbital) It is necessary to constitute by the nonmagnetic material which has an electron.

  First, when the magnetic layer is made of a ferromagnetic material, the magnetic layer has a magnetocrystalline anisotropy and is in a magnetized state in which magnetic moments are aligned in parallel. In addition, by sandwiching the magnetic layer by two nonmagnetic layers made of different materials, the interface between the two magnetic layers and the nonmagnetic layer is spatially asymmetric (does not have inversion symmetry) . When the spatially asymmetric interface is formed, the spin orbit interaction of the nonmagnetic layer causes the Jaroshinski-Moriya interaction near the magnetic layer / nonmagnetic layer interface. The Jaroshinski-Moriya interaction modulates the magnetic exchange interaction acting on the magnetic layer at the magnetic layer-nonmagnetic layer interface. In particular, when the magnetic layer is a thin film formed of several atomic layers, the Jarosinski-Moriya interaction extends from the interface to the surface of the magnetic layer. Due to the modulated magnetic exchange interaction, the magnetic moments of the magnetic layers become more stable in torsion than they are parallel. Thus, skirmions are generated in the magnetic layer.

  The thermoelectric conversion device HD1 of the present embodiment has a structure suitable for generating skirmions in the magnetic material portion MM1. That is, the magnetic material portion MM1 includes the first nonmagnetic layer NM1, the first magnetic layer MG1, and the second nonmagnetic layer NM2. The first magnetic layer MG1 is made of a ferromagnetic material. Furthermore, the first nonmagnetic layer NM1 is made of a nonmagnetic metal having electrons in the f orbital larger in spin-orbit interaction than the other orbitals (s orbital, p orbital, d orbital). The first nonmagnetic layer NM1 and the second nonmagnetic layer NM2 are made of different materials. By doing this, the interface between the first nonmagnetic layer NM1 and the first magnetic layer MG1 and the interface between the first magnetic layer MG1 and the second nonmagnetic layer NM2 become spatially asymmetric, and the first The magnetic exchange interaction acting on the magnetic layer MG1 is modulated by the Jarosinski-Moriya interaction. As a result, as shown in FIGS. 4 and 5A, skirmion SK is generated in the first magnetic layer MG1.

  The magnetic material portion MM1 of the present embodiment has a laminated structure of a first magnetic layer MG1 made of CoFeB and a second nonmagnetic layer NM2 made of magnesium oxide. By doing this, the first magnetic layer MG1 has magnetic anisotropy in the direction perpendicular to the surface (the thickness direction of the first magnetic layer MG1). That is, as shown in FIG. 4, the magnetic moment in the first magnetic layer MG1 is in a magnetization state aligned in the perpendicular direction (z-axis direction in FIG. 4). As a result, when the Jaroshinski-Moriya interaction is extended to the first magnetic layer MG1 in this state, skirmion SK is easily generated in the first magnetic layer MG1.

  If the skyrmion SK generated in the first magnetic layer MG1 can be moved to the conversion portion CV, magnetic energy can be extracted as electric energy. However, gain can not be obtained just by moving the skyrmion SK through the isotropic potential. In addition, since the skyrmions SK generated in the first magnetic layer MG1 randomly move in the first magnetic layer MG1 due to thermal fluctuation, the probability of the skyrmions SK moving to the conversion portion CV is low. Therefore, in order to enhance the efficiency of converting the magnetic energy possessed by Skirmion into electrical energy, the thermoelectric conversion device HD1 of the present embodiment has the following features.

  First, prepare anisotropic potential for skyrmion. As described above, skirmions are generated by the competition between the magnetic exchange interaction and the Jaroshinski-Moriya interaction, so if one of the interactions becomes too large, the skirmions do not exist stably. Therefore, if it is possible to form a structure capable of gradually increasing either the magnetic exchange interaction or the Jaroshinski-Moriya interaction within the range where the skyrmion can be stably present, it is anisotropic to the skyrmion. Potential can be formed.

  Therefore, as shown in FIG. 2, in the present embodiment, the film thickness of the first magnetic layer MG1 is directed in the longitudinal direction of the magnetic material portion MM1 while the film thickness of the first nonmagnetic layer NM1 is constant. It is configured to be thicker according to. Since the first magnetic layer MG1 is made of a ferromagnetic material, the magnetic exchange interaction increases as the film thickness of the first magnetic layer MG1 increases. That is, as the film thickness of the first magnetic layer MG1 increases, the potential for the skirmion SK increases. Therefore, as shown in FIGS. 5A and 5B, a potential gradient with respect to the skirmion SK can be formed along the longitudinal direction of the magnetic material portion MM1.

  As a result, the skyrmions SK generated in the first magnetic layer MG1 move randomly in the first magnetic layer MG1 due to thermal fluctuation, but move to a location where the film thickness of the first magnetic layer MG1 is large. As it does, the magnetic energy which Skirmion SK has becomes large. For example, as shown in FIGS. 5A and 6A, the skyrmion SK is observed from a region where the observation portion OB1 of the first magnetic layer MG1 is formed (hereinafter referred to as an observation portion OB1 formation region) As shown in FIGS. 5 (b) and 6 (b), the magnetic energy of the skyrmion SK increases when moving to the area where the part OB2 is formed (hereinafter referred to as the observation part OB2 formation area). Recognize.

  Next, as shown in FIG. 2, in the present embodiment, a plurality of observation portions OB are provided along the longitudinal direction of the magnetic material portion MM1. As described above, the observation unit OB of the present embodiment is for observing the magnetization state of the first magnetic layer MG1. The specific observation method is as follows. As shown in FIG. 5A, consider the case where skirmion SK is generated in the first magnetic layer MG1. At this time, a voltage is applied between the electrodes of the observation units OB1, OB2, and OB3. As a result, in the observation unit OB1 in which the skyrmion SK is present, the resistance value between the electrodes of the observation unit OB1 is smaller than in the absence of the skyrmion SK. From this, it can be seen that skirmion SK is present in the observation area OB1 formation region in the first magnetic layer MG1.

  Further, as shown in FIG. 6A, consider the case where the skyrmion SK generated in the first magnetic layer MG1 moves from the formation area of the observation part OB1 to the formation area of the observation part OB2. As described above, a voltage is applied to each electrode M1 of the observation units OB1, OB2, and OB3. As a result, in the observation unit OB1 in which the skyrmion SK is not present, the resistance value between the electrodes of the observation unit OB1 increases, and in the observation unit OB2 in which the skyrmion SK is present, the resistance value between the electrodes of the observation unit OB2 is Decrease. From this, it can be seen that the skyrmion SK has moved from the observation portion OB1 formation region in the first magnetic layer MG1 to the observation portion OB2 formation region.

  Further, as shown in FIG. 7A, the skyrmion SK generated in the first magnetic layer MG1 is a region where the observation portion OB3 is formed from the observation portion OB2 formation region (hereinafter referred to as the observation portion OB3 formation region Consider the case of moving to As described above, a voltage is applied to each electrode M1 of the observation units OB1, OB2, and OB3. As a result, in the observation unit OB2 where the skyrmion SK is not present, the resistance value between the electrodes of the observation unit OB2 increases, and in the observation unit OB3 where the skyrmion SK is present, the resistance value between the electrodes of the observation unit OB3 is Decrease. Further, in the observation unit OB1 in which the skyrmion SK does not exist, the resistance value between the electrodes of the observation unit OB1 does not change. Thus, it can be seen that the skyrmion SK has moved from the formation area of the observation part OB2 in the first magnetic layer MG1 to the formation area of the observation part OB3.

  As described above, the observation of the magnetization structure of the magnetic material portion MM1 by the observation portions OB1, OB2, and OB3 provided along the longitudinal direction of the magnetic material portion MM1 enables the observation of the skyrmion SK in the magnetic material portion MM1. It is possible to grasp the generation and movement of Skillmion SK. As mentioned above, although the number of observation parts OB of thermoelectric conversion device HD1 is not limited, it is preferred that at least three observation parts OB1, OB2, and OB3 are formed. In order to detect the skyrmion SK easily and accurately, it is preferable that the distance between the observation units OB be as short as possible.

  Next, as shown in FIG. 2, in the present embodiment, a plurality of control parts GT are provided along the longitudinal direction of the magnetic material part MM1. In particular, the control parts GT are alternately arranged with the observation parts OB along the longitudinal direction of the magnetic material part MM1. As described above, the control unit GT of the present embodiment is for modulating the magnetization state of the first magnetic layer MG1 to control the magnetic stability in the first magnetic layer MG1.

  The specific control method of this magnetic stability is as follows. As shown in FIG. 6A, it is assumed that skirmion SK is present in the observation portion OB2 formation region in the first magnetic layer MG1. The potential for skyrmion SK at this time is shown in FIG. 6 (b). Here, a voltage is applied between the electrodes of the control unit GT1. Thereby, as shown in FIG. 6C, the magnetic anisotropy of the interface between the first magnetic layer MG1 and the second nonmagnetic layer NM2 is changed, and the control portion GT1 in the first magnetic layer MG1 is changed. The potential for the skyrmion SK of the region in which (1) is formed (hereinafter referred to as the control unit GT1 formation region) is increased. That is, when a voltage is applied between the electrodes of the control unit GT1, it becomes difficult for the skyrmion SK to intrude into the control unit GT1 formation region of the first magnetic layer.

  On the other hand, when the application of the voltage between the electrodes of the control unit GT1 is stopped, the potential of the control unit GT1 formation region with respect to the skyrmion SK decreases, and the voltage application to the control unit GT1 as shown in FIG. Return to the previous state. As described above, the control unit GT1 acts as a gate that controls the movement of the skirmion SK in the first magnetic layer MG1 by applying a voltage between the electrodes of the control unit GT1. The magnetic stability of the first magnetic layer MG1 can be controlled by the same mechanism in the control unit GT2 hereinafter.

  Hereinafter, a specific example in which the control unit GT controls the skillion SK will be described. As shown in FIG. 6A, consider the case where the skyrmion SK generated in the first magnetic layer MG1 moves from the formation area of the observation part OB1 to the formation area of the observation part OB2. As shown in FIG. 6B, the energy of the skyrmion SK moved to the observation area OB2 formation area is larger than that of the skylmion (hereinafter referred to as skylmion SK101) existing in the observation area OB1 formation area. .

  At this time, as described above, when the control unit GT grasps that the skyrmion SK exists in the observation unit OB2 formation region in the first magnetic layer MG1 based on the observation result of the observation unit OB, observation is performed. A voltage is applied between the electrodes of the control part GT1 located on the potential energy side smaller than the part OB2 formation region. As a result, as shown in FIG. 6C, the potential of the control portion GT1 formation region in the first magnetic layer MG1 with respect to the skyrmion SK is increased. That is, when a voltage is applied between the electrodes of the control unit GT1, it becomes difficult for the skyrmion SK to intrude into the control unit GT1 formation region of the first magnetic layer, and the skyrmion SK is smaller than the observation region OB2 formation region The probability of moving to the potential energy side is very low. As a result, since the skyrmion SK can not return to the observation area OB1 formation area, the energy difference between the skyrmion SK101 and the skyrmion SK, ie, the observation area OB1 formation area in the first magnetic layer MG1 The heat absorbed to move to the observation part OB2 formation region is accumulated in the skyrmion SK as a gain .DELTA.E1.

  Further, as shown in FIG. 7A, consider the case where the skyrmion SK generated in the first magnetic layer MG1 moves from the formation area of the observation part OB2 to the formation area of the observation part OB3. As shown in FIG. 7B, the energy of the skyrmion SK moved to the observation area OB3 formation area is larger than that of the skyrmion (hereinafter referred to as skylmion SK102) existing in the observation area OB2 formation area. .

  At this time, in the same manner as described above, when the control unit GT determines that the skyrmion SK exists in the region where the observation portion OB3 is formed in the first magnetic layer MG1 based on the observation result of the observation portion OB, observation is performed. A voltage is applied between the electrodes of the control unit GT2 located on the potential energy side smaller than the region where the unit OB3 is formed. As a result, as shown in FIG. 7C, the potential of the region in which the control unit GT2 is formed (hereinafter referred to as the control unit GT2 formation region) with respect to the skyrmion SK increases as described above, and the skyrmion SK is observed The probability of moving to the side of the potential energy smaller than the formation area of the part OB3 is very low. As a result, since the skyrmion SK can not return to the observation area OB2 formation area, the energy difference between the skyrmion SK102 and the skyrmion SK, ie, the observation area OB2 formation area in the first magnetic layer MG1 The heat absorbed to move to the observation part OB3 formation region is accumulated in the skyrmion SK as a gain .DELTA.E2. Note that control is performed until a voltage is applied between the electrodes of the control unit GT2 so that the skyrmion SK does not return to the observation unit OB1 formation region from the observation unit OB2 formation region in the first magnetic layer MG1. It is preferable to maintain a state in which a voltage is applied between the electrodes of part GT1.

  As described above, by controlling the magnetic stability of the magnetic material portion MM1 by the control portions GT1 and GT2 provided along the longitudinal direction of the magnetic material portion MM1, the magnetic stability of the skyrmion SK in the magnetic material portion MM1 is controlled. Movement can be controlled.

  Next, as shown in FIG. 2, in the present embodiment, the conversion portion CV is adjacent to the side of the magnetic material portion MM1 in the lengthwise direction where the film thickness of the first magnetic layer MG1 is largest. Provided. As described above, the skyrmion SK existing in the observation portion OB3 formation region in the first magnetic layer MG1 has a very low probability of moving to the observation portion OB2 formation region by the control portion GT2. Therefore, the skyrmion SK has a high probability of contacting the electrode M3 of the conversion unit CV adjacent to the observation region OB3 formation region of the first magnetic layer MG1. When the skyrmion SK contacts the electrode M3, the inverse spin Hall effect causes the skyrmion SK to disappear and an electromotive force is generated at the electrode M3. As described above, the magnetic energy of the skyrmion SK can be converted into electrical energy by the conversion unit CV adjacent to the observation unit OB3 formation region. As described above, if the skyrmion SK moves from the formation area of the observation part OB1 in the first magnetic layer MG1 to the formation area of the observation part OB3 and then reaches the conversion part CV, as shown in FIG. As shown, the gain ΔE3 stored in the skyrmion can be extracted as electrical energy.

  Summarizing the above, the thermoelectric conversion device HD1 of the present embodiment enables the skyrmion SK to move through the first magnetic layer MG1 having a potential gradient in the direction of movement of the skyrmion SK, thereby making the skyrmion SK Can change the energy of The energy can be accumulated in the skillion SK by controlling the movement of the skillion SK by the control units GT1 and GT2 while observing the movement of the skillion SK by the observation units OB1, OB2, and OB3. Then, the energy stored in the skyrmion SK can be taken out as electric energy by the conversion unit CV. Thus, the thermoelectric conversion device HD1 of the present embodiment can recover heat as energy without a temperature difference.

  Although the case where one skirmion SK exists in the first magnetic layer MG1 has been described as an example, the present invention is not limited to this, and a plurality of skirmions may be simultaneously present in the first magnetic layer MG1. it can. For example, as shown in FIG. 7D, a case will be considered where a new skirmion SK2 is generated in the area where the observation part OB1 is formed in the first magnetic layer MG1. In this case, while the voltage is applied between the electrodes of the control unit GT2 to confine the skyrmion SK in the observation area OB3 formation area, the movement of the skyrmion SK2 to the observation area OB2 formation area is observed. And based on the observation result, a voltage is applied between the electrodes of control part GT1, and skyrmion SK2 is confined in observation part OB2 formation field. In this way, multiple skill mions can be controlled simultaneously. However, from the viewpoint of easily controlling the skirmion SK, it is preferable that the skirmion SK be generated one by one in each of the areas in the first magnetic layer MG1 in which the observation part OB is formed. By optimizing the film thickness of each of the first nonmagnetic layer NM1, the first magnetic layer MG1, and the second nonmagnetic layer NM2, a region where the observation portion OB is formed in the first magnetic layer MG1 You can generate one for each.

  Further, as shown in FIG. 3A, in the present embodiment, the barrier portions BA1 and BA2 are formed at both ends in the width direction of the first magnetic layer MG1, and the widthwise center of the first magnetic layer MG1 is formed. The skillmion generation unit SP is formed so as to be sandwiched between the barrier units BA1 and BA2. The film thickness of the first magnetic layer MG1 included in the barrier portions BA1 and BA2 is larger than the film thickness of the first magnetic layer MG1 included in the skyrmion generating portion SP. As described above, since the first magnetic layer MG1 is made of a ferromagnetic material, when the film thickness of the first magnetic layer MG1 becomes large, the magnetic exchange interaction becomes large. That is, when the film thickness of the first magnetic layer MG1 is increased, the potential for the skirmion SK is increased.

  Therefore, as shown in FIG. 3B, in the width direction of the magnetic material portion MM1, the potential of the region where the barrier portions BA1 and BA2 are formed (hereinafter referred to as the barrier portion BA1 and BA2 formation region) to the skyrmion SK. Is larger than a region in which the skyrmion generation portion SP is formed (hereinafter referred to as a skyrmion generation portion SP formation region) (a so-called well potential). As a result, the skyrmions SK present in the first magnetic layer MG1 can be stably present in the skyrmion generation portion SP formation region in the width direction of the magnetic material portion MM1, while in the barrier portions BA1 and BA2 formation region It becomes difficult to invade.

  As a result, in the magnetic material portion MM1 of the present embodiment, the skyrmions SK generated in the first magnetic layer MG1 can be confined in the skyrmion generating portion SP formation region in the width direction of the first magnetic layer MG1. . Therefore, the skirmion SK can be stably moved along the longitudinal direction of the first magnetic layer MG1.

[Modification]
A thermoelectric conversion device HD2 which is a modification of the above embodiment will be described with reference to FIG. FIG. 8 is a cross-sectional view at a position corresponding to the line AA of FIG. 1 of the thermoelectric conversion device HD2 of the modification.

  The thermoelectric conversion device HD2 of the modification shown in FIG. 8 includes the substrate SUB and the insulating film IL1 formed on the substrate SUB, which is the same as the thermoelectric conversion device HD1 of the above embodiment. .

  In the case of the thermoelectric conversion device HD2 of the modified example, the configuration of the magnetic material portion MM2 is different from the configuration of the magnetic material portion MM1 of the above embodiment. Specifically, the magnetic material portion MM2 is the same as the magnetic material portion MM1 in that it is composed of the first nonmagnetic layer NM1, the first magnetic layer MG1, and the second nonmagnetic layer NM2. On the other hand, the film thickness of the first nonmagnetic layer NM1 included in the magnetic material portion MM2 is configured to be thicker as it goes in the longitudinal direction (first direction) of the magnetic material portion MM2, and the first magnetic layer MG1 is formed. The film thickness is different from the magnetic material portion MM1 of the above embodiment in that the film thickness is constant along the longitudinal direction of the magnetic material portion MM2.

  The film thickness of the first magnetic layer MG1 is, for example, about 1 to 10 nm, and preferably about 1.3 nm. The film thickness of the second nonmagnetic layer NM2 is, for example, about 1 to 10 nm, and preferably about 1.4 nm. The film thickness of the first nonmagnetic layer NM1 is about 1 to 2 nm at the thinnest portion and about 10 nm at the thickest portion. The thickness of the first nonmagnetic layer NM1 is the length direction of the magnetic material portion MM2. It is getting thicker at a constant rate. The potential gradient with respect to the skyrmion SK of the thermoelectric conversion device HD2 of the modification is the same as the potential gradient of the thermoelectric conversion device HD1 of the above embodiment shown in FIG. 5B with respect to the skyrmion SK.

  As described above, skirmions are generated by the competition between the magnetic exchange interaction and the Jaroshinski-Moriya interaction, so if one of the interactions becomes too large, the skirmions do not exist stably. Since the first nonmagnetic layer NM1 is made of nonmagnetic metal having electrons in the f orbital, which has a spin orbital interaction constant larger than that of other orbitals (s orbital, p orbital, d orbital), the first nonmagnetic layer As the film thickness of NM1 increases, the Jaroshinski-Moriya interaction increases. That is, as the film thickness of the first nonmagnetic material layer NM1 increases, the potential for the skirmion SK increases. Therefore, in the thermoelectric conversion device HD2 of the modification, the film thickness of the first nonmagnetic layer NM1 included in the magnetic material portion MM2 is configured to be thicker in the longitudinal direction of the magnetic material portion MM2, Similar to the thermoelectric conversion device HD1 of the embodiment, a potential gradient with respect to the skirmion SK can be formed along the longitudinal direction of the magnetic material portion MM2.

  While the thermoelectric conversion device HD1 of the above embodiment changes the film thickness of the first magnetic layer MG1 along the length direction, the thermoelectric conversion device HD2 of the modification example has the first nonmagnetic member. The film thickness of the body layer NM1 is changed along the length direction. Therefore, the thermoelectric conversion device according to the above-described embodiment is provided according to the manufacturing cost, the ease of the process, and the like in the manufacturing process when forming the semiconductor device SD on the same substrate SUB as the heat transport system HS described later. HD1 and the thermoelectric conversion device HD2 of the above-described modified example can be arbitrarily selected.

[About the structure of the heat transport system]
The heat transport system HS of the present embodiment will be described. FIG. 9 is a block diagram of the heat transport system HS of the present embodiment. As shown in FIG. 9, the heat transport system HS of this embodiment includes a semiconductor device SD generating heat, a cooling device CD for cooling the semiconductor device SD, the thermoelectric conversion device HD1, and the thermoelectric conversion device HD1. And an energy storage device ES for storing the output electrical energy. Although not shown, the semiconductor device SD, the thermoelectric conversion device HD1, the energy storage device ES, and the cooling device CD, which constitute the heat transport system HS, may be formed on the same substrate SUB or formed on different substrates. It may be done. However, in order to efficiently exchange heat and electrical energy between the semiconductor device SD, the thermoelectric conversion device HD1, the energy storage device ES, and the cooling device CD, they are formed on the same substrate SUB. Is preferred.

  The semiconductor device SD is, for example, a semiconductor device having a memory or a semiconductor device forming a switching element. When the semiconductor device SD has, for example, a memory, the read / write to the memory generates heat from the semiconductor device SD. Further, also when the semiconductor device SD constitutes a switching element of a power device, heat is generated from the semiconductor device SD.

  The cooling device CD is, for example, a cooling device such as a liquid-cooled cooler or a cooling fan that uses a circulating cooling medium (refrigerant).

  The energy storage device ES is a device that stores the supplied electrical energy. The energy storage device ES is a device that has, for example, a capacitor and a charging circuit, stores the supplied electric energy in the capacitor, and outputs the electric energy as needed.

  Hereinafter, the operation of the heat transport system HS of the present embodiment will be described. First, heat is generated from the semiconductor device SD due to the operation of the semiconductor device SD. Next, this heat is supplied to the thermoelectric conversion device HD1. Thereafter, as described above, electric energy is extracted from the supplied heat by the thermoelectric conversion device HD1.

  Subsequently, the electrical energy output from the thermoelectric conversion device HD1 is supplied to the energy storage device ES, and the electrical energy is stored. The electrical energy stored in the energy storage device ES is supplied to the cooling device CD or the semiconductor device SD. The cooling device CD operates by the electrical energy supplied from the energy storage device ES and cools the semiconductor device SD. Further, the electrical energy supplied from the energy storage device ES to the semiconductor device SD is reused for the operation of the semiconductor device SD.

  As described above, the heat transport system HS of the present embodiment can efficiently utilize the heat generated from the semiconductor device SD as electrical energy for cooling the semiconductor device SD and for the operation of the semiconductor device SD. As a result, the heat transport system HS of the present embodiment can efficiently recover exhaust heat as energy.

  The energy storage device ES of the present embodiment may be configured as part of the thermoelectric conversion device HD1. Further, in the heat transport system HS of the present embodiment, the thermoelectric conversion device HD2 of the above modification may be employed instead of the thermoelectric conversion device HD1.

  As mentioned above, although the invention made by the present inventor was concretely explained based on an embodiment, the present invention is not limited to the above-mentioned embodiment, and can be variously changed in the range which does not deviate from the gist. Needless to say.

BA1, BA2 barrier part CD cooling device CV conversion part ES energy storage device GT, GT1, GT2 control part HD1, HD2 thermoelectric conversion device HS heat transport system IL1, IL2 insulating film M1, M2, M3 electrode MG1 first magnetic layer MG2 Second magnetic layer MM1, MM2 Magnetic material portion NM1 First nonmagnetic layer NM2 Second nonmagnetic layer OB, OB1, OB2, OB3 Observation portion SD Semiconductor device SK, SK2 Skirmion SP Skirmion generation part SUB Substrate

Claims (15)

Magnetic material section,
An observation unit that observes a change in the magnetization state of the magnetic material unit;
A control unit that controls the magnetization state of the magnetic material unit;
A conversion unit for converting magnetic energy in the magnetic material unit into electrical energy;
Equipped with
The magnetic material portion is formed on a first nonmagnetic layer made of a nonmagnetic material, a first magnetic layer formed on the first nonmagnetic layer, and made of a magnetic material, and on the first magnetic layer. A second nonmagnetic layer formed of a nonmagnetic material different from the first nonmagnetic material layer;
The thermoelectric conversion device, wherein the film thickness of the first magnetic layer is increased in the first direction. In the thermoelectric conversion device according to claim 1,
In the first magnetic layer, skirmions are generated due to the thermal fluctuation of the magnetic material portion,
The observation unit detects the position of the skyrmion in the first magnetic layer,
The control unit controls the skirmion only in the direction in which the first magnetic layer having a thickness larger than the thickness of the first magnetic layer at the position of the skirmion detected by the observation unit is present. Thermoelectric converter, which controls to move. In the thermoelectric conversion device according to claim 2,
The magnetic material portion is formed in a rectangular shape in plan view,
The thermoelectric conversion device, wherein the observation unit and the control unit are alternately arranged along the length direction of the magnetic material unit. In the thermoelectric conversion device according to claim 3,
The widthwise end of the first magnetic layer is thicker than the widthwise center of the first magnetic layer,
The thermoelectric conversion device, wherein the skyrmion moves along a width direction central portion of the first magnetic material layer along a length direction of the magnetic material portion. In the thermoelectric conversion device according to claim 3,
The observation unit includes the first nonmagnetic layer, the first magnetic layer on the first nonmagnetic layer, the second nonmagnetic layer on the first magnetic layer, and the first nonmagnetic layer. 2. A thermoelectric conversion device comprising a second magnetic layer formed on a nonmagnetic layer and an electrode formed on the second magnetic layer. In the thermoelectric conversion device according to claim 3,
The control unit includes: the first nonmagnetic layer; the first magnetic layer on the first nonmagnetic layer; the second nonmagnetic layer on the first magnetic layer; 2. A thermoelectric conversion device comprising an electrode formed on a nonmagnetic layer. In the thermoelectric conversion device according to claim 3,
The thermoelectric conversion device, wherein the conversion unit is made of nonmagnetic metal having electrons in the f orbital. In the thermoelectric conversion device according to claim 3,
The first nonmagnetic layer is made of nonmagnetic metal having electrons in the f orbital,
The thermoelectric conversion device, wherein the second nonmagnetic layer is made of a nonmagnetic insulator. In the thermoelectric conversion device according to claim 8,
The first nonmagnetic layer is made of Pt or Ta,
The first magnetic layer is made of CoFeB,
The thermoelectric conversion device, wherein the second nonmagnetic layer is made of MgO. Magnetic material section,
An observation unit that observes a change in the magnetization state of the magnetic material unit;
A control unit that controls the magnetization state of the magnetic material unit;
A conversion unit for converting magnetic energy in the magnetic material unit into electrical energy;
Equipped with
The magnetic material portion is formed on a first nonmagnetic layer made of a nonmagnetic material, a first magnetic layer formed on the first nonmagnetic layer, and made of a magnetic material, and on the first magnetic layer. A second nonmagnetic layer formed of a nonmagnetic material different from the first nonmagnetic material layer;
The thermoelectric conversion device, wherein the film thickness of the first nonmagnetic material layer increases in the first direction. In the thermoelectric conversion device according to claim 10,
In the first magnetic layer, skirmions are generated due to the thermal fluctuation of the magnetic material portion,
The observation unit detects the position of the skyrmion in the first magnetic layer,
The control unit is configured to perform the first nonmagnetic layer only in the direction in which the first nonmagnetic layer has a film thickness larger than the film thickness of the first nonmagnetic layer at the position of the skyrmion detected by the observation unit. A thermoelectric converter that controls the skill mion to move. In the thermoelectric conversion device according to claim 11,
The magnetic material portion is formed in a rectangular shape in plan view,
The thermoelectric conversion device, wherein the observation unit and the control unit are alternately arranged along the length direction of the magnetic material unit. A thermoelectric converter,
A semiconductor device,
A cooling device,
Have
The thermoelectric conversion device is
Magnetic material section,
An observation unit that observes a change in the magnetization state of the magnetic material unit;
A control unit that controls the magnetization state of the magnetic material unit;
A conversion unit for converting magnetic energy in the magnetic material unit into electrical energy;
Equipped with
Supplying heat generated from the semiconductor device to the thermoelectric conversion device;
Converting the heat into electrical energy by the thermoelectric converter;
Supplying the electrical energy to the cooling device;
A heat transport system, wherein the semiconductor device is cooled by the cooling device. In the heat transport system according to claim 13,
The magnetic material portion is formed on a first nonmagnetic layer made of a nonmagnetic material, a first magnetic layer formed on the first nonmagnetic layer, and made of a magnetic material, and on the first magnetic layer. A second nonmagnetic layer formed of a nonmagnetic material different from the first nonmagnetic material layer;
The heat transport system, wherein the film thickness of the first magnetic layer is thicker toward the first direction. In the heat transport system according to claim 14,
The magnetic material portion is formed in a rectangular shape in plan view,
The observation unit and the control unit are alternately arranged along the longitudinal direction of the magnetic material unit,
In the first magnetic layer, skirmions are generated due to the thermal fluctuation of the magnetic material portion,
The observation unit detects the position of the skyrmion in the first magnetic layer,
The control unit controls the skirmion only in the direction in which the first magnetic layer having a thickness larger than the thickness of the first magnetic layer at the position of the skirmion detected by the observation unit is present. Control heat transfer system to move.

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