Thermoelectric conversion element and sensor

Abstract

A thermoelectric conversion element (1a) is provided with a thermoelectric conversion body (11) and a connection section (12). The thermoelectric conversion body (11) includes a conductive magnetic body having a ferromagnet or an antiferromagnet exhibiting an abnormal Nernst effect, and extends linearly. The connection part (12) includes a conductor and is electrically connected to the thermoelectric conversion body (11). The connection part (12) has a laminated structure (12k) of a plurality of conductive layers. The laminated structure (12k) includes a first conductive layer (12p) and a second conductive layer (12q). The first conductive layer (12p) has a Seebeck coefficient lower than the Seebeck coefficient (Sm) of the conductive magnetic body contained in the thermoelectric conversion body (11). The second conductive layer (12q) has a Seebeck coefficient higher than the Seebeck coefficient (Sm).

Description

Technical Field

[0001] The present invention relates to a thermoelectric conversion element and a sensor. Background Art

[0002] Conventionally, technologies related to magnetothermoelectric conversion are known.

[0003] For example, a thermoelectric power generation device utilizing the anomalous Nernst effect is described in Patent Document 1. The anomalous Nernst effect is a phenomenon in which a voltage is generated in a direction orthogonal to both the magnetization direction and the temperature gradient when heat flows through a magnetic body and a temperature difference is generated.

[0004] The thermoelectric generator comprises a substrate, a generator, and a connector. The generator comprises a plurality of thin wires arranged parallel to one another along the surface of the substrate. Each thin wire is formed by thinning an FePt thin film formed on the substrate and is magnetized in the width direction. The generator is constructed so as to generate electricity by utilizing a temperature difference perpendicular to the magnetization direction through the anomalous Nernst effect. The connector is formed by a plurality of thin wires arranged parallel to the thin wires of the generator along the surface of the substrate and between the thin wires. Each thin wire of the connector electrically connects one end of each thin wire of the generator to the other end of a thin wire adjacent to one side of each thin wire. Thus, the connector electrically connects the thin wires of the generator in series. The connector is formed, for example, of Cr, a non-magnetic material.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2014-072256 Summary of the Invention

[0008] Problems to be solved by the invention

[0009] The demand for heat-related monitoring is increasing, including in areas such as monitoring physical conditions in the Internet of Things (IoT) society and thermal management in technical fields such as electric vehicle (EV) batteries and high-speed data processing chips. To meet this demand, the use of thermoelectric conversion elements for thermal sensing is being considered.

[0010] It is understood that thermoelectric conversion elements utilizing magnetoelectric conversion, such as the thermoelectric conversion device described in Patent Document 1, can be easily manufactured compared to thermoelectric generators utilizing the Seebeck effect. Based on these advantages, the use of thermoelectric conversion elements utilizing magnetoelectric conversion for thermal sensing is being considered.

[0011] In the thermoelectric converter described in Patent Document 1, the generator is constructed to generate electricity by utilizing a temperature difference perpendicular to the magnetization direction. On the other hand, in thermoelectric converter elements utilizing magnetothermoelectric conversion, it is assumed that an electromotive force is generated by a mechanism different from magnetothermoelectric conversion. For example, in the thermoelectric converter described in Patent Document 1, when a temperature gradient is generated along the longitudinal direction of the thin wires of the generator formed of a FePt thin film and the thin wires of the connector formed of a non-magnetic Cr material, the difference between the Seebeck coefficients of FePt and Cr may lead to the generation of a thermoelectric force associated with the Seebeck effect along the longitudinal direction. From the perspective of thermal sensing accuracy, it is difficult to say that the generation of such a thermoelectric force is beneficial. This is because the electromotive force associated with magnetothermoelectric conversion and the electromotive force associated with the Seebeck effect are superimposed. In addition, in order to increase the thermoelectric force associated with the magnetothermoelectric effect, the thermoelectric converter described in Patent Document 1 electrically connects the connector formed of multiple thin wires and the generator formed of multiple thin wires in series. In such a configuration, the electromotive force associated with the Seebeck effect is likely to increase, which may significantly affect the accuracy of thermal sensing.

[0012] Magnetothermoelectric coefficient S ne Use resistivity ρ xx , transverse magneto-thermoelectric coefficient α xy , Seebeck coefficient S se , and the Hall conductivity σ xy and σ xx , by S ne =ρ xx α xy -S se ·σ xy / σ xx Therefore, it can be understood that from the perspective of improving the performance of magnetothermoelectric conversion, the Seebeck coefficient S se The material with a large absolute value is favorable. se Large material, thus the magneto-thermoelectric coefficient S ne On the other hand, the Seebeck coefficient S se For large materials, it is easy to generate electromotive force based on the temperature difference in the plane direction, which is easy to affect the accuracy of thermal sensing. Although attempts have been made to use materials with large Seebeck S, such as Co2MnGa, se Although Heusler alloys with high coefficients are used in magnetothermoelectric conversion elements, no research has been conducted on how to deal with such issues.

[0013] In view of such circumstances, the present invention provides a thermoelectric conversion element which is advantageous from the viewpoint of utilizing magneto-thermoelectric conversion and improving the accuracy of thermal sensing.

[0014] Means for solving problems

[0015] The present invention provides a thermoelectric conversion element comprising:

[0016] A thermoelectric converter comprising a conductive magnetic body having a ferromagnet or antiferromagnet exhibiting an anomalous Nernst effect and extending linearly; and

[0017] a connecting portion comprising a conductor and electrically connected to the thermoelectric converter;

[0018] The connecting portion has a stacked structure of multiple conductive layers.

[0019] The laminated structure includes a first conductive layer having a Seebeck coefficient lower than that of the conductive magnetic body and a second conductive layer having a Seebeck coefficient higher than that of the conductive magnetic body.

[0020] The present invention provides a thermoelectric conversion element comprising:

[0021] A thermoelectric converter comprising a conductive magnetic body having a ferromagnet or antiferromagnet exhibiting an anomalous Nernst effect and extending linearly; and

[0022] a connecting portion comprising a conductor and electrically connected to the thermoelectric converter;

[0023] The connecting portion has a stacked structure of multiple conductive layers.

[0024] An absolute value of a difference between a Seebeck coefficient of the connecting portion and a Seebeck coefficient of the conductive magnetic body is 5 μV / K or less.

[0025] Effects of the Invention

[0026] The above-mentioned thermoelectric conversion element is advantageous from the viewpoint of utilizing magneto-thermoelectric conversion and improving the accuracy of thermal sensing. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] [ Figure 1 ] Figure 1 It is a perspective view showing an example of an embodiment of a thermoelectric conversion element.

[0028] [ Figure 2 ] Figure 2 It will Figure 1 A cross-sectional view of the thermoelectric conversion element with plane II shown as the cross section.

[0029] [ Figure 3 ] Figure 3 This is a cross-sectional view showing another example of a thermoelectric conversion element.

[0030] [ Figure 4 ] Figure 4 This is a cross-sectional view showing another example of a thermoelectric conversion element.

[0031] [ Figure 5 ] Figure 5 This is a cross-sectional view showing another example of a thermoelectric conversion element. DETAILED DESCRIPTION

[0032] The embodiments of the present invention will be described with reference to the accompanying drawings. It should be noted that the present invention is not limited to the following embodiments. In the accompanying drawings, the X-axis, Y-axis, and Z-axis are orthogonal to each other.

[0033] like Figure 1 As shown, the thermoelectric conversion element 1a includes a thermoelectric converter 11 and a connection portion 12. The thermoelectric converter 11 includes a conductive magnetic body having a ferromagnetic or antiferromagnetic structure exhibiting an anomalous Nernst effect and extends linearly. The connection portion 12 includes a conductor and is electrically connected to the thermoelectric converter 11. Figure 2 As shown, the connection portion 12 has a stacked structure 12k of multiple conductive layers. The stacked structure 12k includes, for example, a first conductive layer 12p and a second conductive layer 12q. The first conductive layer 12p has a Seebeck coefficient S higher than that of the conductive magnetic material contained in the thermoelectric converter 11. m The second conductive layer 12q has a Seebeck coefficient S m High Seebeck coefficient. The Seebeck coefficient of each conductive layer of the stacked structure 12k and the Seebeck coefficient S m For example, it is a value under conditions of 25 to 40° C. and can be measured according to the method described in the Examples. The thermoelectric converter 11 and the connection portion 12 are arranged along a surface parallel to the XY plane, for example.

[0034] In the thermoelectric conversion element 1a, if a temperature gradient occurs in the longitudinal direction (Y-axis direction) of the thermoelectric converter 11, the Seebeck coefficient S of the connecting portion 12 L and Seebeck coefficient S m Since the connection portion 12 has a stacked structure 12k including a first conductive layer 12p and a second conductive layer 12q, the Seebeck coefficient S of the connection portion 12 is L The Seebeck coefficient of the connecting portion 12 may be a value between the Seebeck coefficient of the first conductive layer 12p and the Seebeck coefficient of the second conductive layer 12q. L and Seebeck coefficient S mThe difference between the two is easily reduced, and even if a temperature gradient occurs along the longitudinal direction of the thermoelectric converter 11, the thermoelectromotive force associated with the Seebeck effect generated along its longitudinal direction is easily reduced. Therefore, in sensing using the thermoelectric converter element 1a, the electromotive force associated with the Seebeck effect, which is superimposed on the electromotive force associated with magnetoelectric conversion, is easily reduced. As a result, the thermoelectric converter element 1a is advantageous from the perspective of achieving high-precision thermal sensing using magnetoelectric conversion.

[0035] In the case where the connection portion electrically connected to the thermoelectric converter including the conductive magnetic body is composed of only a single conductive layer, it is possible to consider making the Seebeck coefficient of the conductor forming the conductive layer close to the Seebeck coefficient of the conductive magnetic body. For example, it is possible to consider adjusting the Seebeck coefficient of the conductive layer by adjusting the composition of the components contained in the single conductive layer. However, in this case, due to the fluctuation of the composition of the components contained in the single conductive layer, the Seebeck coefficient of the conductive layer may also fluctuate significantly, and it may be impossible to exert good robustness. In addition, even if the Seebeck coefficient of the conductive layer can be adjusted to a value close to the Seebeck coefficient of the conductive magnetic body, since the composition of the conductive layer is uniquely determined, it will also be restricted in achieving other characteristics such as durability of the conductive layer.

[0036] On the other hand, the inventors of this application have newly discovered that the Seebeck coefficient of a stacked structure can be roughly predicted based on the Seebeck coefficient, resistivity, and thickness of each layer of the stacked structure. L The Seebeck coefficient of the first conductive layer 12p can be set to a value between the Seebeck coefficient of the second conductive layer 12q. In this case, for example, by adjusting the thickness of the first conductive layer 12p and the thickness of the second conductive layer 12q, the Seebeck coefficient S of the connecting portion 12 can be reduced. L and Seebeck coefficient S m Thus, according to the thermoelectric conversion element 1a, the Seebeck coefficient S at the connection portion 12 is L There are few restrictions on the conductor in the adjustment, and the Seebeck coefficient S L Furthermore, as the conductor included in the connection portion 12, a favorable material can be selected from the viewpoint of durability and other characteristics, thereby easily increasing the added value of the thermoelectric conversion element 1a.

[0037] In the thermoelectric conversion element 1a, the Seebeck coefficient S of the connection portion 12 is L and Seebeck coefficient S m The absolute value of the difference |S L -S m |Not limited to a specific value. Absolute value|S L -S m| For example, 5 μV / K or less. In this case, the thermoelectric conversion element 1a is advantageous from the viewpoint of realizing high-precision thermal sensing by utilizing magneto-thermoelectric conversion. The Seebeck coefficient S of the connecting portion 12 is L For example, it refers to a value under conditions of 25 to 40° C. and can be measured according to the method described in the Examples.

[0038] In the thermoelectric conversion element 1a, |S L -S m |It can be 4.8μV / K or less, 4.5μV / K or less, 4.0μV / K or less, 3.5μV / K or less, or 3.0μV / K or less. |S L -S m |It can be 2.5 μV / K or less, 2.0 μV / K or less, 1.0 μV / K or less, 0.5 μV / K or less, or 0.3 μV / K or less.

[0039] In the thermoelectric conversion element 1a, the number n of the plurality of conductive layers included in the stacked structure 12k is not limited to a specific value. Figure 2 As shown, in the stacked structure 12 k , n=2 may be used, and the stacked structure 12 k may be composed of only two conductive layers, namely the first conductive layer 12 p and the second conductive layer 12 q . Figure 3 This is a cross-sectional view showing another example of a thermoelectric conversion element. Figure 3 The thermoelectric conversion element 1b shown in FIG. 1 is constructed in the same manner as the thermoelectric conversion element 1a except for the parts specifically described. Figure 3 As shown, in the stacked structure 12k, n=3 may be sufficient, and the stacked structure 12k may further include a third conductive layer 12r. The stacked structure 12k may include four or more conductive layers. The number n of conductive layers included in the stacked structure 12k may be, for example, 10 or less, or 5 or less.

[0040] The thermoelectric conversion element 1a satisfies the conditions shown in the following formulas (1), (2), and (3). In formulas (1) to (3), n is an integer greater than or equal to 2, which is the number of the plurality of conductive layers in the stacked structure 12k. i is an integer from 1 to n. i is the thickness [m] of the i-th conductive layer in the stacking order in the stacked structure 12k. i is the specific resistance of the i-th conductive layer [Ω·m]. i is the Seebeck coefficient of the i-th conductive layer [V / K], S m The first term on the left side of formula (1) is based on the new insight obtained by the inventors of this application, that is, the Seebeck coefficient S of the stacked structure 12k can be predicted based on the thickness and resistivity of each conductive layer. LIn other words, the first term on the left side of equation (1) corresponds to the Seebeck coefficient S of the stacked structure 12k. L In the thermoelectric conversion element 1a, by satisfying such conditions, the thermoelectric conversion element 1a is more advantageous from the viewpoint of realizing high-precision thermal sensing by utilizing magneto-thermoelectric conversion.

[0041] [Mathematical formula 1]

[0042]

[0043] G i =t i / ρ i (3)

[0044] In the thermoelectric conversion element 1a, the left side of formula (1) may be 4.8 μV / K or less, 4.5 μV / K or less, 4.0 μV / K or less, 3.5 μV / K or less, or 3.0 μV / K or less. The left side may be 2.5 μV / K or less, 2.0 μV / K or less, 1.0 μV / K or less, 0.5 μV / K or less, or 0.3 μV / K or less.

[0045] The thermoelectric conversion element 1a satisfies the conditions shown in the following formulas (4) and (5), for example. In formula (4), n is an integer greater than or equal to 2, which is the number of the plurality of conductive layers in the stacked structure 12k. i is an integer from 1 to n. i is the thickness [m] of the i-th conductive layer in the stacking order in the stacked structure 12k. i is the specific resistance of the i-th conductive layer [Ω·m]. σ i is the conductivity of the i-th conductive layer [S / m]. When the thermoelectric conversion element 1a satisfies such a condition, the Seebeck coefficient S of the connecting portion 12 can be L By adjusting the thickness to a desired range, it is possible to prevent the thicknesses of the plurality of conductive layers of the stacked structure 12k from being greatly different from each other. In this case, the thermoelectric conversion element 1a is advantageous from the viewpoint of robustness.

[0046] [Mathematical formula 2]

[0047]

[0048] G i =t i / ρ i (5)

[0049] The value of the central physical quantity in formula (4) may be 0.12 or more, 0.15 or more, or 0.18 or more. The value of the central physical quantity in formula (4) may be 8 or less, 6 or less, 4 or less, or 2 or less.

[0050] In the stacked structure 12k, the arithmetic mean value S of the Seebeck coefficients of the plurality of conductive layers of the stacked structure 12k is AVG The Seebeck coefficient S of the conductive magnetic material contained in the thermoelectric converter 11 is m The absolute value of the difference |S AVG -S m |Not limited to a specific value. Absolute value|S AVG -S m | For example, it is 10 μV / K or less. In this case, it is easy to reduce the Seebeck coefficient S of the connecting portion 12 to L Adjusting the temperature within a desired range is advantageous also in terms of robustness of the thermoelectric conversion element 1a.

[0051] Absolute value|S AVG -S m |It can be 8 μV / K or less, 6 μV / K or less, 4 μV / K or less, 2 μV / K or less, or 1 μV / K or less.

[0052] In the thermoelectric conversion element 1a, the stacked structure 12k satisfies the conditions shown in the following equations (6), (7), and (8). In equations (6) to (8), n is an integer greater than or equal to 2, which is the number of the plurality of conductive layers in the stacked structure 12k. i is an integer from 1 to n. i is the thickness [m] of the i-th conductive layer in the stacking order in the stacked structure 12k. i is the specific resistance of the i-th conductive layer [Ω·m]. m is the conductivity [S] in the longitudinal direction of the conductive magnetic body. When these conditions are met, the stacked structure 12k tends to have high conductivity. Therefore, when using the thermoelectric conversion element 1a and utilizing magnetic thermoelectric conversion for thermal sensing, a high output power is easily obtained, and the sensitivity of thermal sensing tends to be increased. Whether the condition of equation (6) holds true can be determined, for example, by comparing the stacked structure 12k and the thermoelectric converter 11 of the same length in the longitudinal direction (Y-axis direction).

[0053] [Mathematical formula 3]

[0054] Y / G m ≥3 (6)

[0055]

[0056] Gi =t i / ρ i (8)

[0057] The left side of the formula (6) may be 3.5 or more, 4.0 or more, or 4.5 or more. The left side of the formula (6) may be 20 or less, for example.

[0058] The material forming the conductive layer of stacked structure 12k is not limited to a specific material. For example, the conductive layer forming the surface layer of stacked structure 12k may contain at least 10% atomic percent of at least one element selected from the group consisting of Ti, Cr, Ni, Al, Zn, Nb, Pd, Ag, Ta, W, Pt, and Au. In this case, the conductive layer forming the surface layer tends to have high durability. For example, when thermoelectric converter element 1a is manufactured using a method including photolithography, the conductive layer forming the surface layer is resistant to corrosion even in the highly alkaline environment associated with photolithography.

[0059] In the stacked structure 12k, the content of at least one element selected from the group consisting of Cu, Al, Ag, and Au in at least one of the multiple conductive layers is 50% or greater, based on the number of atoms. In this case, the stacked structure 12k tends to have high electrical conductivity. Therefore, when using the thermoelectric conversion element 1a and performing thermal sensing using magnetoelectric conversion, high output power is easily achieved, and thermal sensing sensitivity is easily enhanced.

[0060] In the stacked structure 12k, at least one of the multiple conductive layers can comprise a single metal. In this case, the precursor of the conductive layer is easily etched by commercially available etching solutions, making the manufacture of the thermoelectric conversion element 1a easier. Furthermore, while alloys of multiple metals can provide corrosion resistance, this can limit the available etching solutions. Consequently, achieving etching selectivity with magnetic materials can be difficult, potentially restricting the element formation process. The multiple conductive layers can comprise alloys.

[0061] The thermoelectric converter 11 includes, for example, a substance exhibiting an anomalous Nernst effect. The substance exhibiting an anomalous Nernst effect is not limited to a specific substance. For example, a substance exhibiting an anomalous Nernst effect has a 5×10 -3 A magnetic material having a saturation magnetic susceptibility of T or higher, or a material having a Weyl point band structure near the Fermi level. The thermoelectric converter 11 contains, for example, at least one material selected from the group consisting of the following (i), (ii), (iii), (iv), and (v) as a material exhibiting the anomalous Nernst effect.

[0062] (i) Stoichiometric substances having the composition shown as Fe3X

[0063] (ii) Non-stoichiometric substances in which the composition ratio of Fe to X deviates from that of the substance in (i) above

[0064] (iii) A substance in which a portion of the Fe sites of the substance of (i) above or a portion of the Fe sites of the substance of (ii) above are replaced by a typical metal element or transition element other than X

[0065] (iv) with Fe3M1 1-x M2 x A material having a composition shown as (0<x<1), and M1 and M2 are different typical elements

[0066] (v) A substance in which a portion of the Fe site of the substance of (i) above is replaced by a transition element other than X, and a portion of the X site of the substance of (i) above is replaced by a typical metal element other than X.

[0067] In the substances (i) to (v) above, X is a typical element or a transition element. Examples of X include Al, Ga, Ge, Sn, Si, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Sc, Ni, Mn, or Co. In (iv) above, the combination of M1 and M2 is not limited to a specific combination as long as M1 and M2 are different typical elements. In (iv) above, examples of the combination of M1 and M2 include Ga and Al, Si and Al, or Ga and B.

[0068] The thermoelectric converter 11 may contain Co2MnGa or an antiferromagnet as a substance exhibiting the anomalous Nernst effect. An example of the antiferromagnet is Mn3Sn.

[0069] The thermoelectric converter 11 may be an alloy containing Fe and having a body-centered cubic lattice crystal structure. In this case, a large electromotive force due to the anomalous Nernst effect is easily generated in the thermoelectric converter 11.

[0070] When the thermoelectric converter 11 is an alloy containing Fe and having a body-centered cubic lattice structure, the Fe content and the content of elements other than Fe in the alloy are not limited to specific values. For example, the Fe content in the alloy is 50% or more, and the content of elements other than Fe in the alloy is 10% or more, based on the number of atoms. In this case, a large electromotive force due to the anomalous Nernst effect is easily generated in the thermoelectric converter 11.

[0071] The Fe content in the alloy may be 55% or more, 60% or more, 65% or more, or 70% or more, based on the number of atoms. The Fe content in the alloy may be 90% or less, 85% or less, or 80% or less, based on the number of atoms.

[0072] The content of elements other than Fe in the above alloys may be 15% or more, or 20% or more, based on the number of atoms. The content of elements other than Fe in the above alloys may be 50% or less, or 40% or less, or 30% or less, based on the number of atoms.

[0073] The magnetoelectric coefficient S of the thermoelectric converter 11 NE The magnetoelectric coefficient S of the thermoelectric converter 11 is not limited to a specific value. NE The absolute value of is, for example, 0.5 μV / K or more. As a result, in the thermoelectric converter 11, it is easy to generate a large electromotive force by utilizing magneto-thermoelectric conversion, and it is easy to improve the accuracy of sensing using the thermoelectric converter element 1a. Therefore, it is easy to detect small amounts of heat. The magneto-thermoelectric coefficient S of the thermoelectric converter 11 is NE The absolute value of is preferably 1.0 μV / K or more, more preferably 1.5 μV / K or more, and even more preferably 2.0 μV / K or more. The magnetoelectric coefficient S of the thermoelectric converter 11 is NE The absolute value of can be 3.0 μV / K or more, 4.0 μV / K or more, 5.0 μV / K or more, 6.0 μV / K or more, 7.0 μV / K or more, or 8.0 μV / K or more.

[0074] like Figure 1 and Figure 2 As shown, for example, thermoelectric converter 11 includes multiple first thin wires 11a. Furthermore, connecting portion 12 includes multiple second thin wires 12a. In thermoelectric converter element 1a, multiple first thin wires 11a and multiple second thin wires 12a are electrically connected in series. This configuration synthesizes the electromotive force generated by multiple first thin wires 11a during magneto-thermoelectric conversion, making it easier for thermoelectric converter element 1a to achieve high output power.

[0075] like Figure 2As shown, in the thermoelectric conversion element 1a, a plurality of first thin wires 11a and a plurality of second thin wires 12a form, for example, a plurality of thin wire pairs 15. Each thin wire pair 15 includes a first thin wire 11a and a second thin wire 12a. In other words, each thin wire pair 15 includes one first thin wire 11a and one second thin wire 12a. The number of thin wire pairs 15 in the thermoelectric conversion element 1a is not limited to a specific value. In the thermoelectric conversion element 1a, a plurality of first thin wires 11a and a plurality of second thin wires 12a form, for example, more than 50 pairs of thin wire pairs 15. The greater the number of pairs of joined dissimilar materials, the greater the electromotive force due to the Seebeck effect. On the other hand, according to the stacked structure 12k of the thermoelectric conversion element 1a, even if the thermoelectric conversion element 1a has more than 50 pairs of thin wire pairs 15, when a temperature gradient is generated in the long side direction of the thermoelectric converter 11, the thermoelectromotive force associated with the Seebeck effect generated in the long side direction is likely to become smaller.

[0076] like Figure 1 and Figure 2 As shown, the plurality of first thin wires 11a and the plurality of second thin wires 12a form a zigzag pattern. With this configuration, even if the area of ​​the plane where the plurality of first thin wires 11a and the plurality of second thin wires 12a are arranged is small, it is easy to obtain a high output from the thermoelectric conversion element 1a.

[0077] like Figure 1 As shown, the plurality of first thin wires 11a are separated by prescribed intervals in the X-axis direction and are arranged in parallel with each other. The plurality of first thin wires 11a are arranged at equal intervals in the X-axis direction. The plurality of second thin wires 12a electrically connects the first thin wires 11a adjacent to each other in the X-axis direction, for example. The second thin wire 12a electrically connects one end of the first thin wire 11a in the Y-axis direction and the other end of another first thin wire 11a adjacent to the first thin wire 11a in the Y-axis direction, for example. The one end of the plurality of first thin wires 11a in the Y-axis direction is located at the end on the same side of the first thin wire 11a in the Y-axis direction, and the other end of the plurality of first thin wires 11a in the Y-axis direction is located at the end of the first thin wire 11a on the opposite side of the one end in the Y-axis direction.

[0078] The thickness of the first fine wires 11a is not limited to a specific value. For example, the first fine wires 11a have a thickness of 1000 nm or less. This reduces the amount of material used to form the magnetic thermoelectric converter in the thermoelectric conversion element 1a, making it easier to reduce the manufacturing cost of the thermoelectric conversion element 1a. Furthermore, in the thermoelectric conversion element 1a, disconnection of the conductive path formed by the plurality of first fine wires 11a and the plurality of second fine wires 12a is less likely to occur.

[0079] The thickness of the first fine wire 11a can be 750 nm or less, 500 nm or less, 400 nm or less, 300 nm or less, or 200 nm or less. For example, the thickness of the first fine wire 11a is 5 nm or more. This facilitates high durability of the thermoelectric conversion element 1a. The thickness of the first fine wire 11a can be 10 nm or more, 20 nm or more, 30 nm or more, or 50 nm or more.

[0080] The dimension of the first fine wire 11a in the X-axis direction, i.e., its width, is not limited to a specific value. The width of the first fine wire 11a is, for example, 500 μm or less. This reduces the amount of material used to form the magnetic thermoelectric converter in the thermoelectric conversion element 1a, making it easier to reduce the manufacturing cost of the thermoelectric conversion element 1a. Furthermore, it is easier to arrange multiple first fine wires 11a in the X-axis direction, which increases the electromotive force generated by the magnetic thermoelectric conversion in the thermoelectric conversion element 1a.

[0081] The width of the first fine wire 11a can be 400 μm or less, 300 μm or less, 200 μm or less, 100 μm or less, or 50 μm or less. The width of the first fine wire 11a is, for example, 0.1 μm or more. As a result, disconnection of the conductive path is less likely to occur in the thermoelectric conversion element 1a, and the thermoelectric conversion element 1a can easily exhibit high durability. The width of the first fine wire 11a can be 0.5 μm or more, 1 μm or more, 2 μm or more, 5 μm or more, 10 μm or more, 20 μm or more, or 30 μm or more.

[0082] The thickness of the second thin wire 12a is not limited to a specific value. The thickness of the second thin wire 12a is, for example, 1000 nm or less. This can reduce the amount of material used to form the connecting portion 12, making it easy to reduce the manufacturing cost of the thermoelectric conversion element 1a. In addition, disconnection of the conductive path is less likely to occur in the thermoelectric conversion element 1a. The thickness of the second thin wire 12a can be 750 nm or less, 500 nm or less, 400 nm or less, 300 nm or less, 200 nm or less, or 100 nm or less.

[0083] The thickness of the second thin wire 12a is, for example, 5 nm or more. This allows the thermoelectric conversion element 1a to easily exhibit high durability. The thickness of the second thin wire 12a can be 10 nm or more, 20 nm or more, 30 nm or more, or 50 nm or more.

[0084] The maximum dimension, i.e., the width, of the second thin wire 12a in the X-axis direction is not limited to a specific value. The width of the second thin wire 12a is, for example, 500 μm or less. This reduces the amount of material used to form the connection portion 12 in the thermoelectric conversion element 1a, making it easier to reduce the manufacturing cost of the thermoelectric conversion element 1a. Furthermore, it is easier to arrange multiple second connection portions 12a in the X-axis direction, which increases the electromotive force generated by the magneto-thermoelectric conversion in the thermoelectric conversion element 1a.

[0085] The width of the second fine wire 12a can be 400 μm or less, 300 μm or less, 200 μm or less, 100 μm or less, or 50 μm or less. The width of the second fine wire 12a is, for example, 0.1 μm or more. As a result, disconnection of the conductive path is less likely to occur in the thermoelectric conversion element 1a, and the thermoelectric conversion element 1a is likely to exhibit high durability. The width of the second fine wire 12a can be 0.5 μm or more, 1 μm or more, 2 μm or more, 5 μm or more, 10 μm or more, 20 μm or more, or 30 μm or more.

[0086] like Figure 1 As shown, the thermoelectric conversion element 1 a further includes a substrate 20 . The thermoelectric converter 11 and the connection portion 12 are disposed on the substrate 20 .

[0087] The material constituting the substrate 20 is not limited to a specific material. For example, the substrate 20 does not contain MgO in its surface layer. This eliminates the need to contain MgO in the surface layer of the substrate 20, thus reducing the complexity of manufacturing the thermoelectric conversion element 1a and making it easier to achieve acid resistance.

[0088] The substrate 20 is, for example, flexible. In this case, the shape of the object on which the thermoelectric conversion element 1a can be mounted is not easily restricted. When the substrate 20 is flexible, the substrate 20 contains, for example, at least an organic polymer. As a result, it is easy to reduce the manufacturing cost of the thermoelectric conversion element 1a. Examples of organic polymers are polyethylene terephthalate (PET), polyethylene naphthalate (PEN), acrylic resin (PMMA), polycarbonate (PC), polyimide (PI) or cycloolefin polymer (COP). The substrate 20 can also be ultra-thin plate glass. An example of ultra-thin plate glass is G-Leaf (registered trademark) manufactured by Nippon Electric Glass Co., Ltd.

[0089] An example of a method for manufacturing the thermoelectric converter element 1a is described. First, a thin film of a precursor of the thermoelectric converter 11 is formed on one main surface of the substrate 20 using a method such as sputtering, chemical vapor deposition (CVD), pulsed laser deposition (PLD), ion plating, and a plating method. Next, a photoresist is applied to the thin film, a photomask is placed on the thin film, exposure is performed, and then wet etching is performed. Thus, a linear pattern of a plurality of precursors of the thermoelectric converter 11 arranged at predetermined intervals is formed. Next, a thin film of a precursor of the stacked structure 12k is formed on one main surface of the substrate 20 using a method such as sputtering, CVD, PLD, ion plating, and a plating method. In the formation of the thin film of the precursor of the stacked structure 12k, for example, after forming a thin film of the precursor of the first conductive layer 12p, a thin film of the precursor of the second conductive layer 12p is formed on the thin film. Next, a photoresist is applied to the thin film of the precursor of the stacked structure 12k, a photomask is placed over the thin film of the precursor of the stacked structure 12k, and exposure is performed, followed by wet etching. This results in a connection portion 12 having the stacked structure 12k, electrically connecting the linear patterns of the precursor of the thermoelectric converter 11. Next, the precursor of the thermoelectric converter 11 is magnetized to form the thermoelectric converter 11. This results in the thermoelectric converter element 1a. If desired, the precursor of the connection portion 12 can also be magnetized to form the connection portion 12. Alternatively, wet etching of the thin film of the precursor of the conductive layer can be performed for each conductive layer in the stacked structure 12k.

[0090] Thermoelectric conversion element 1a may be provided with an adhesive layer, for example. In this case, substrate 20 is disposed between thermoelectric converter 11 and the adhesive layer in the thickness direction of substrate 20. Thus, thermoelectric conversion element 1a can be attached to an article by pressing the adhesive layer against the article.

[0091] The adhesive layer comprises, for example, a rubber-based adhesive, an acrylic adhesive, a silicone-based adhesive, or a urethane-based adhesive. The thermoelectric conversion element 1a may also be provided together with an adhesive layer and a release liner. In this case, the release liner covers the adhesive layer. Typically, the release liner is a film that can maintain the adhesive strength of the adhesive layer when covering the adhesive layer and can be easily peeled off from the adhesive layer. The release liner is, for example, a film made of a polyester resin such as PET. By peeling off the release liner, the adhesive layer can be exposed and the thermoelectric conversion element 1a can be attached to an article.

[0092] A sensor including a thermoelectric converter element 1a can be provided. In this sensor, when a temperature gradient occurs in the thickness direction of substrate 20, for example, an electromotive force is generated in the longitudinal direction of thermoelectric converter 11 by utilizing the magnetoelectric effect. The sensor can sense heat flux by processing an electrical signal output to the outside of thermoelectric converter element 1a based on this electromotive force.

[0093] The thermoelectric conversion element 1a can be modified from various viewpoints. For example, the thermoelectric conversion element 1a can be Figure 4 The thermoelectric conversion element 1c shown or Figure 5 1a. Except for the parts otherwise noted, thermoelectric conversion elements 1c and 1d have the same configuration as thermoelectric conversion element 1a. Components of thermoelectric conversion elements 1c and 1d that are identical or corresponding to those of thermoelectric conversion element 1a are denoted by the same reference numerals, and detailed descriptions are omitted. The description of thermoelectric conversion element 1a also applies to thermoelectric conversion elements 1c and 1d, unless technically inconsistent.

[0094] like Figure 4 As shown, in thermoelectric converter element 1c, thermoelectric converter 11 extends continuously on the same plane, for example. A laminated structure 12k of connecting portion 12 is disposed on a portion of thermoelectric converter 11. For example, a plurality of second thin wires 12a are disposed on thermoelectric converter 11 at predetermined intervals. This configuration easily reduces the thermoelectromotive force associated with the Seebeck effect, thereby reducing the manufacturing cost of the thermoelectric converter element.

[0095] In the thermoelectric conversion element 1c, the thermoelectric converter 11 has, for example, a zigzag pattern and is configured such that a single layer of the thermoelectric converter 11 and a stacked body including the thermoelectric converter 11 and the second thin wires 12a appear alternately in the X-axis direction.

[0096] like Figure 5 As shown, in the thermoelectric conversion element 1d, the laminated structure 12k of the connecting portion 12 extends continuously on the same plane, for example. The thermoelectric converter 11 is disposed on a portion of the laminated structure 12k of the connecting portion 12. For example, a plurality of first thin wires 11a are disposed at predetermined intervals on the laminated structure 12k of the connecting portion 12. This configuration easily reduces the thermoelectromotive force associated with the Seebeck effect, thus reducing the manufacturing cost of the thermoelectric conversion element.

[0097] In thermoelectric conversion element 1d, laminated structure 12k of connection portion 12 forms a zigzag pattern, for example. In thermoelectric conversion element 1c, connection portions 12 and laminated bodies including connection portions 12 and first thin wires 11a appear alternately in the X-axis direction.

[0098] Example

[0099] The present invention will be described in more detail below using examples. However, the present invention is not limited to the following examples. First, the evaluation methods related to the examples and comparative examples will be described.

[0100] [Determination of Seebeck coefficient]

[0101] The Seebeck coefficient S of the magnetoelectric conversion wire in the thermoelectric conversion element according to each embodiment and each comparative example was measured at 27 to 37°C in the longitudinal direction using a small refrigerant-free physical property measurement system PPMS VersaLab manufactured by Quantum Design. m , and the Seebeck coefficient S at 27 to 37°C in the longitudinal direction of the wiring (connection portion) L . In addition, the Seebeck coefficients of the first conductive layer and the second conductive layer in the wiring at 27 to 37°C were measured using samples prepared separately. Each Seebeck coefficient was determined based on the electromotive force and temperature difference induced between the two thermometers installed on the sample when a heat flow was generated using a heater installed at one end of each sample. The Seebeck coefficients of the materials constituting each conductive layer forming the wiring at 27 to 37°C are shown in Table 1. In addition, the arithmetic mean value S of the Seebeck coefficients of the conductive layers constituting the wiring was AVG As shown in Table 2, the Seebeck coefficient S m and Seebeck coefficient S L Shown in Table 2.

[0102] [Determination of magneto-thermoelectric coefficient]

[0103] The Nernst coefficient of the thin film constituting the thermoelectric converter wire for magnetothermoelectric conversion in the thermoelectric converter elements of each Example and each Comparative Example was measured at 27 to 37°C using the small refrigerant-free physical property measurement system PPMSVersaLab manufactured by Quantum Design. NE 2.0μV / K.

[0104] [Measurement of specific resistance]

[0105] Using the non-contact resistance measuring device NC-80MAP manufactured by NAPSON, in accordance with Japanese Industrial Standard JIS Z2316-1: 2014, according to the eddy current measurement method, the sheet resistance of each film used for wiring was measured for each embodiment and each comparative example. The product of the sheet resistance of each film measured in this way and the thickness of each film was calculated to determine the specific resistance of each conductive layer. In addition, the reciprocal of the specific resistance of each conductive layer was determined as the conductivity. The results are shown in Table 1. In addition, the specific resistance of the thermoelectric converter constituting the fine wire for magneto-thermoelectric conversion was measured in the same manner. Based on the measurement results, the conductivity G in the long side direction of a fine wire for magneto-thermoelectric conversion was calculated. m The results are shown in Table 2.

[0106] [Prediction of Seebeck coefficient]

[0107] Based on the specific resistance and thickness of each conductive layer, the predicted value S of the Seebeck coefficient of the wiring (connection portion) is calculated according to the following equations (9) and (10):P The results are shown in Table 2. In formulas (9) and (10), t1 and t2 are the thicknesses of the first and second conductive layers, respectively. ρ1 and ρ2 are the specific resistances of the first and second conductive layers, respectively, in Ω·m. S1 and S2 are the Seebeck coefficients of the materials constituting the first and second conductive layers, respectively, in V / K.

[0108] S P ={(t1 / ρ1) / Y}×S1+{(t2 / ρ2) / Y}×S2 (9)

[0109] Y=(t1 / ρ1)+(t2 / ρ2) (10)

[0110] [Measurement of electromotive force associated with the Seebeck effect]

[0111] In each example and comparative example, the thermoelectric conversion element was heated with a heater at one end of the thermoelectric conversion wire and wiring in the longitudinal direction, creating a 1°C temperature difference between the two ends of the thermoelectric conversion wire and wiring (connection portion) in the longitudinal direction. Under this condition, the electromotive force Vs associated with the Seebeck effect was measured. During this measurement, the temperature of both surfaces of the thermoelectric conversion element was maintained constant, with the exception of one end of the thermoelectric conversion wire and wiring in the longitudinal direction, to prevent a temperature gradient from occurring in the thickness direction of the thermoelectric conversion element. The results are shown in Table 2.

[0112] [Processability]

[0113] Processability is evaluated based on wet etching performance. A solution is prepared by mixing MEC's ​​Cu etching solution SF-5420, NIHON KAGAKU SANGYO CO., LTD.'s nickel-selective etching solution NC, or Melstrip TI-3991 from Meltex, hydrogen peroxide, and water in a volume ratio of 1:2:2. If the laminated film comprising the first and second conductive layers can be dissolved in these solutions, the processability is evaluated as "A." If the laminated film cannot be dissolved in these solutions, the processability is evaluated as "X." It should be noted that when the processability is evaluated as "X," the photolithography process is performed using a solution consisting of nitric acid and hydrogen peroxide mixed in a specified ratio.

[0114] Durability

[0115] The laminated film comprising the first and second conductive layers was immersed in a 5% by mass NaOH solution for 1 minute, and the appearance of the laminated film was then observed. If discoloration was observed on the surface of the laminated film, the durability was rated "X." If no discoloration was observed on the surface of the laminated film, the durability was rated "A."

[0116] <Example 1>

[0117] Using a target material containing Fe and Ga, a thin film with a thickness of 100 nm is formed on a polyethylene terephthalate (PET) film with a thickness of 50 μm by DC magnetron sputtering. In this target material, the content of Fe: the content of Ga is in a relationship of 3:1 in terms of atomic ratio. A photoresist is applied to the film, a photomask is arranged on the film, exposed, and then wet-etched. Thus, 94 fine wires for magneto-thermoelectric conversion are formed, which are arranged parallel to each other at a prescribed interval. The width of each fine wire for magneto-thermoelectric conversion is 100 μm, and the length of each fine wire for magneto-thermoelectric conversion is 15 mm. Then, using a target material of Cu, a first conductive layer with a thickness of 10 nm is formed by DC magnetron sputtering. Next, using a target material of Ni, a second conductive layer with a thickness of 101 nm is formed on the first conductive layer by DC magnetron sputtering. A photoresist is applied to a laminate film comprising a first conductive layer and a second conductive layer, a photomask is placed on the laminate film for exposure, and then wet etching is performed. Thus, a wiring (connecting portion) having a width of 40 μm is formed. The wiring is used to electrically connect a plurality of magnetothermoelectric conversion wires in series. In addition, a plurality of magnetothermoelectric conversion wires and the wiring form a zigzag pattern. The magnetothermoelectric conversion wires are magnetized in a direction parallel to the plane of the PET film and orthogonal to the long side direction of the magnetothermoelectric conversion wires to obtain the thermoelectric conversion element of Example 1. The thermoelectric conversion element generates an electromotive force based on the anomalous Nernst effect.

[0118] <Example 2>

[0119] The thermoelectric conversion element of Example 2 was produced in the same manner as Example 1, except for the following points. A target having a Cu content:Ni content ratio of 91:9 was used instead of the Cu target. This target was used to form a first conductive layer having a thickness of 98 nm by DC magnetron sputtering. A target having a Cu content:Ni content ratio of 66:34 was used instead of the Ni target. A second conductive layer having a thickness of 35 nm was formed on top of the first conductive layer by DC magnetron sputtering.

[0120] <Example 3>

[0121] A thermoelectric conversion element of Example 3 was produced in the same manner as Example 2 except for the following points: a first conductive layer having a thickness of 92 nm was formed by DC magnetron sputtering using a target having a Cu content:Ni content relationship of 91:9 in atomic ratio.

[0122] <Example 4>

[0123] A thermoelectric conversion element of Example 4 was produced in the same manner as Example 2 except for the following points: a first conductive layer having a thickness of 84 nm was formed by DC magnetron sputtering using a target having a Cu content:Ni content relationship of 91:9 in atomic ratio.

[0124] <Example 5>

[0125] A thermoelectric conversion element of Example 5 was produced in the same manner as Example 2 except for the following points: a first conductive layer having a thickness of 77 nm was formed by DC magnetron sputtering using a target having a Cu content:Ni content relationship of 91:9 in atomic ratio.

[0126] <Example 6>

[0127] A thermoelectric conversion element of Example 6 was produced in the same manner as in Example 2 except for the following points: a first conductive layer having a thickness of 72 nm was formed by DC magnetron sputtering using a target having a Cu content:Ni content relationship of 91:9 in atomic ratio.

[0128] <Example 7>

[0129] A thermoelectric conversion element of Example 7 was produced in the same manner as Example 2 except for the following points: a first conductive layer having a thickness of 67 nm was formed by DC magnetron sputtering using a target having a Cu content:Ni content relationship of 91:9 in atomic ratio.

[0130] <Example 8>

[0131] A thermoelectric conversion element of Example 8 was produced in the same manner as Example 2 except for the following points: a first conductive layer having a thickness of 63 nm was formed by DC magnetron sputtering using a target having a Cu content:Ni content relationship of 91:9 in atomic ratio.

[0132] <Example 9>

[0133] A thermoelectric conversion element of Example 9 was produced in the same manner as in Example 2 except for the following points: a first conductive layer having a thickness of 59 nm was formed by DC magnetron sputtering using a target having a Cu content:Ni content relationship of 91:9 in atomic ratio.

[0134] <Example 10>

[0135] A thermoelectric conversion element of Example 10 was produced in the same manner as in Example 2 except for the following points: a first conductive layer having a thickness of 52 nm was formed by DC magnetron sputtering using a target having a Cu content:Ni content relationship of 91:9 in atomic ratio.

[0136] <Example 11>

[0137] A thermoelectric conversion element according to Example 11 was produced in the same manner as in Example 1, except for the following points. A target having a Cu content of 66:34 (in atomic ratio) was used instead of the Cu target. This target was used to form a first conductive layer having a thickness of 35 nm by DC magnetron sputtering. A target having a Cu content of 91:9 (in atomic ratio) was used instead of the Ni target. This target was used to form a second conductive layer having a thickness of 98 nm on top of the first conductive layer by DC magnetron sputtering.

[0138] <Example 12>

[0139] The thermoelectric conversion element of Example 12 was produced in the same manner as in Example 1, except for the following points. A Ti target was used instead of a Cu target. This target was used to form a first conductive layer having a thickness of 77 nm by DC magnetron sputtering. A target having a Cu content of 44:Ni atomic ratio of 56 was used instead of a Ni target. This target was used to form a second conductive layer having a thickness of 45 nm on top of the first conductive layer by DC magnetron sputtering.

[0140] Comparative Example 1

[0141] A thermoelectric conversion element of Comparative Example 1 was produced in the same manner as in Example 1, except for the following points. A Ni target was used instead of a Cu target. This target was used to form a first conductive layer having a thickness of 101 nm by DC magnetron sputtering. A target having a Cu content of 44:56 in atomic ratio was used instead of the Ni target. This target was used to form a second conductive layer having a thickness of 43 nm on top of the first conductive layer by DC magnetron sputtering.

[0142] Comparative Example 2

[0143] A thermoelectric conversion element of Comparative Example 2 was produced in the same manner as Example 1, except for the following points. A first conductive layer having a thickness of 50 nm was formed by DC magnetron sputtering using a target having an atomic ratio of Fe:Ga = 3:1. A second conductive layer having a thickness of 50 nm was formed on the first conductive layer by DC magnetron sputtering using a target having an atomic ratio of Cu:Ni = 44:56 instead of the Ni target.

[0144] Comparative Example 3

[0145] A thermoelectric conversion element according to Comparative Example 3 was produced in the same manner as in Example 2, except for the following points. A 98 nm thick conductive layer was formed by DC magnetron sputtering using a target having a Cu:Ni atomic ratio of 91:9. A conductive layer corresponding to the second conductive layer in Example 2 was not formed on top of this conductive layer, resulting in a single-layer conductive layer.

[0146] As shown in Table 2, the electromotive force associated with the Seebeck effect in the thermoelectric conversion elements of each example is smaller than that associated with the Seebeck effect in the thermoelectric conversion element of the comparative example. Therefore, it is suggested that the electromotive force associated with the Seebeck effect can be reduced by stacking a structure comprising a conductive layer having a Seebeck coefficient lower than that of the thermoelectric converter and a conductive layer having a Seebeck coefficient higher than that of the thermoelectric converter. Furthermore, it is suggested that from the perspective of reducing the electromotive force associated with the Seebeck effect, it is advantageous for the absolute value of the difference between the Seebeck coefficient of the connecting portion of a stacked structure having multiple conductive layers and the Seebeck coefficient of the conductive magnetic body to be 5 μV / K or less. Furthermore, it is suggested that by appropriately selecting the composition of the outermost layer of the stacked structure of the conductive layers, durability can be improved, and that a stacked structure can achieve both a reduction in the electromotive force associated with the Seebeck effect and durability. In the thermoelectric conversion element of Comparative Example 3, the use of a single conductive layer having a Seebeck coefficient close to that of the thermoelectric converter reduces the electromotive force associated with the Seebeck effect, but results in poor durability.

[0147] A first aspect of the present invention provides a thermoelectric conversion element comprising:

[0148] A thermoelectric converter comprising a conductive magnetic body having a ferromagnet or antiferromagnet exhibiting an anomalous Nernst effect and extending linearly; and

[0149] a connecting portion comprising a conductor and electrically connected to the thermoelectric converter;

[0150] The connecting portion has a stacked structure of multiple conductive layers.

[0151] The laminated structure includes a first conductive layer having a Seebeck coefficient lower than that of the conductive magnetic body and a second conductive layer having a Seebeck coefficient higher than that of the conductive magnetic body.

[0152] A second aspect of the present invention provides a thermoelectric conversion element comprising:

[0153] A thermoelectric converter comprising a conductive magnetic body having a ferromagnet or antiferromagnet exhibiting an anomalous Nernst effect and extending linearly; and

[0154] a connecting portion comprising a conductor and electrically connected to the thermoelectric converter;

[0155] The connecting portion has a stacked structure of multiple conductive layers.

[0156] An absolute value of a difference between a Seebeck coefficient of the connecting portion and a Seebeck coefficient of the conductive magnetic body is 5 μV / K or less.

[0157] The third aspect of the present invention provides the thermoelectric conversion element according to the first or second aspect, wherein the stacked structure satisfies the conditions represented by the following formulae (1), (2), and (3):

[0158] In formulas (1) to (3), n is an integer greater than or equal to 2, which is the number of the plurality of conductive layers in the stacked structure, i is an integer from 1 to n, and t i is the thickness of the i-th conductive layer in the stacking order in the stacked structure, ρ i is the specific resistance of the above-mentioned conductive layer, S i is the Seebeck coefficient of the i-th conductive layer, S m is the Seebeck coefficient of the conductive magnetic material.

[0159] [Formula 4]

[0160]

[0161] G i =t i / ρ i (3)

[0162] A fourth aspect of the present invention provides the thermoelectric conversion element according to any one of the first to third aspects,

[0163] The above-mentioned stacked structure satisfies the conditions shown in the following formulas (4) and (5):

[0164] In formulas (4) and (5), n is an integer greater than or equal to 2, which is the number of the plurality of conductive layers in the stacked structure, i is an integer from 1 to n, and ti is the thickness of the i-th conductive layer in the stacking order in the stacked structure, ρ i is the specific resistance of the i-th conductive layer, σ i is the conductivity of the i-th conductive layer.

[0165] [Formula 5]

[0166]

[0167] G i =t i / ρ i (5)

[0168] The fifth aspect of the present invention provides the thermoelectric conversion element according to any one of the first to fourth aspects, wherein the absolute value of the difference between the arithmetic mean of the Seebeck coefficients of the plurality of conductive layers and the Seebeck coefficient of the conductive magnetic body is 10 μV / K or less.

[0169] A sixth aspect of the present invention provides a thermoelectric conversion element according to any one of aspects 1 to 5, wherein the content of at least one element selected from the group consisting of Ti, Cr, Ni, Al, Zn, Nb, Pd, Ag, Ta, W, Pt and Au in the conductive layer forming the surface layer in the stacked structure is 10% or more based on the number of atoms.

[0170] A seventh aspect of the present invention provides the thermoelectric conversion element according to any one of the first to sixth aspects, wherein the content of at least one selected from the group consisting of Cu, Al, Ag and Au in at least one of the plurality of conductive layers is 50% or more based on the number of atoms.

[0171] The eighth aspect of the present invention provides the thermoelectric conversion element according to any one of the first to seventh aspects, wherein the stacked structure satisfies the conditions represented by the following formulae (6), (7), and (8):

[0172] In formulas (6) to (8), n is an integer greater than or equal to 2, which is the number of the plurality of conductive layers in the stacked structure, i is an integer from 1 to n, and t i is the thickness of the i-th conductive layer in the stacking order in the stacked structure, ρ i is the specific resistance of the i-th conductive layer in the stacking order in the stacked structure, G m is the electrical conductivity in the longitudinal direction of the conductive magnetic body.

[0173] [Formula 6]

[0174] Y / G m ≥3 (6)

[0175]

[0176] G i =t i / ρ i (8)

[0177] A ninth aspect of the present invention provides the thermoelectric conversion element according to any one of the first to eighth aspects, wherein at least one of the plurality of conductive layers comprises a single metal.

[0178] According to a tenth aspect of the present invention, there is provided the thermoelectric conversion element according to any one of the first to ninth aspects, wherein the thermoelectric converter comprises a plurality of first thin wires.

[0179] The connecting portion has a plurality of second thin lines,

[0180] The plurality of first thin wires and the plurality of second thin wires are electrically connected in series.

[0181] According to an eleventh aspect of the present invention, there is provided the thermoelectric conversion element according to the tenth aspect, wherein the plurality of first thin wires and the plurality of second thin wires form 50 or more pairs of thin wires.

[0182] The 50 or more pairs of thin wires respectively include the first thin wire and the second thin wire.

[0183] A twelfth aspect of the present invention provides the thermoelectric conversion element according to the tenth or eleventh aspect, wherein the plurality of first thin wires and the plurality of second thin wires form a zigzag pattern.

[0184] A thirteenth aspect of the present invention provides a sensor including the thermoelectric conversion element according to any one of the first to twelfth aspects.

[0185] [Table 1]

[0186]

[0187] [Table 2]

[0188]

Claims

1. A thermoelectric conversion element comprising: A thermoelectric converter comprising a conductive magnetic body having a ferromagnet or antiferromagnet exhibiting an anomalous Nernst effect and extending linearly; and a connecting portion comprising a conductor and electrically connected to the thermoelectric converter, The connecting portion has a stacked structure of multiple conductive layers. The stacked structure includes a first conductive layer having a Seebeck coefficient lower than that of the conductive magnetic body and a second conductive layer having a Seebeck coefficient higher than that of the conductive magnetic body.

2. A thermoelectric conversion element comprising: A thermoelectric converter comprising a conductive magnetic body having a ferromagnet or antiferromagnet exhibiting an anomalous Nernst effect and extending linearly; and a connecting portion comprising a conductor and electrically connected to the thermoelectric converter, The connecting portion has a stacked structure of multiple conductive layers. An absolute value of a difference between a Seebeck coefficient of the connecting portion and a Seebeck coefficient of the conductive magnetic body is 5 μV / K or less.

3. The thermoelectric conversion element according to claim 1 or 2, wherein The stacked structure satisfies the conditions shown in the following formulas (1), (2) and (3), In formulas (1) to (3), n is an integer of 2 or greater, which is the number of the plurality of conductive layers in the stacked structure; i is an integer from 1 to n; and t i is the thickness of the i-th conductive layer in the stacking order in the stacked structure, ρ i is the specific resistance of the i-th conductive layer, S i is the Seebeck coefficient of the i-th conductive layer, S m is the Seebeck coefficient of the conductive magnetic body, [Mathematical formula 1] G i =t i / r i (3)。 4. The thermoelectric conversion element according to claim 1 or 2, wherein The stacked structure satisfies the conditions shown in the following formulas (4) and (5): In formulas (4) and (5), n is an integer greater than or equal to 2, which is the number of the plurality of conductive layers in the stacked structure; i is an integer from 1 to n; and t i is the thickness of the i-th conductive layer in the stacking order in the stacked structure, ρ i is the specific resistance of the i-th conductive layer, σ i is the conductivity of the i-th conductive layer, [Mathematical formula 2] G i =t i / r i (5)。 5. The thermoelectric conversion element according to claim 1 or 2, wherein An absolute value of a difference between an arithmetic mean value of the Seebeck coefficients of the plurality of conductive layers and a Seebeck coefficient of the conductive magnetic body is 10 μV / K or less.

6. The thermoelectric conversion element according to claim 1 or 2, wherein The content of at least one element selected from the group consisting of Ti, Cr, Ni, Al, Zn, Nb, Pd, Ag, Ta, W, Pt and Au in the conductive layer forming the surface layer in the stacked structure is 10% or more based on the number of atoms.

7. The thermoelectric conversion element according to claim 1 or 2, wherein The content of at least one selected from the group consisting of Cu, Al, Ag, and Au in at least one of the plurality of conductive layers is 50% or more in terms of atomic number.

8. The thermoelectric conversion element according to claim 1 or 2, wherein The stacked structure satisfies the conditions shown in the following formulas (6), (7) and (8), In formulas (6) to (8), n is an integer greater than or equal to 2, which is the number of the plurality of conductive layers in the stacked structure; i is an integer from 1 to n; and t i is the thickness of the i-th conductive layer in the stacking order in the stacked structure, ρ i is the specific resistance of the i-th conductive layer in the stacking order in the stacked structure, G m is the conductivity in the longitudinal direction of the conductive magnetic body, [Mathematical formula 3] Y / G m ≥3 (6) G i =t i / r i (8)。 9. The thermoelectric conversion element according to claim 1 or 2, wherein At least one of the plurality of conductive layers includes a single element of metal.

10. The thermoelectric conversion element according to claim 1 or 2, wherein The thermoelectric converter has a plurality of first thin wires. The connecting portion has a plurality of second thin lines, The plurality of first thin wires and the plurality of second thin wires are electrically connected in series.

11. The thermoelectric conversion element according to claim 10, wherein The plurality of first thin lines and the plurality of second thin lines form more than 50 pairs of thin lines, The 50 or more pairs of thin wires respectively include the first thin wire and the second thin wire.

12. The thermoelectric conversion element according to claim 10, wherein The plurality of first thin lines and the plurality of second thin lines form a zigzag pattern.

13. A sensor comprising the thermoelectric conversion element according to claim 1 or 2.

Images