Thermoelectric conversion device
The thermoelectric conversion efficiency of a thermoelectric conversion device is increased by increasing the figure of merit of a spin-Seebeck effect element. An inverse spin-Hall effect material is provided to at least one end of a thermal spin-wave spin current generating material made of a magnetic dielectric material so that a thermal spin-wave spin current is converted to generate a voltage in the above described inverse spin-Hall effect material when there is a temperature gradient in the above described thermal spin-wave spin current generating material and a magnetic field is applied using a magnetic field applying means.
1. A thermoelectric conversion device comprising:
a thermal spin-wave spin current generating material made of a magnetic dielectric material extending in a direction;
an inverse spin-Hall effect material provided at least one end in said direction of said thermal spin-wave spin current generating material;
a heat source to give temperature gradient in said direction in said thermal spin-wave spin current generating material; and
a magnetic field generator to generate magnetic field in said direction in said thermal spin-wave spin current generating material,
wherein a thermal spin-wave spin current is converted to generate a voltage in said inverse spin-Hall effect material when there is a temperature gradient in said thermal spin-wave spin current generating material, and a magnetic field is applied using said magnetic field generator.
2. The thermoelectric conversion device according to claim 1 , wherein said magnetic dielectric material is made of any of a ferrimagnetic dielectric material, a ferromagnetic dielectric material or an antiferromagnetic dielectric material.
3. The thermoelectric conversion device according to claim 1 , wherein said magnetic dielectric material is made of a ferrimagnetic dielectric material or a ferromagnetic dielectric material, and said magnetic field applying means is an antiferromagnetic layer which makes contact with said magnetic dielectric material and fixes the direction of magnetization of the magnetic dielectric material.
4. The thermoelectric conversion device according to claim 1 , wherein said magnetic dielectric material is made of Y 3 Fe 5-x Ga x O 12 (x<5).
5. The thermoelectric conversion device according to claim 1 , wherein said inverse spin-Hall effect material is made of any of Pt, Au, Pd, Ag, Bi or an element having an f-orbital.
6. The thermoelectric conversion device according to claim 5 , wherein said magnetic dielectric material has a film thickness of 5 nm or more and said inverse spin-Hall effect material has a film thickness of 5 nm to 20 nm.
7. The thermoelectric conversion device according to claim 1 , wherein said inverse spin-Hall effect material is provided in different plural positions in the longitudinal direction of said thermal spin-wave spin current generating material.
8. A thermoelectric conversion device comprising a plurality of thermoelectric conversion sub-elements, one or more thermoelectric conversion sub-elements comprising:
a thermal spin-wave spin current generating material made of a magnetic dielectric material extending in a direction;
an inverse spin-Hall effect material provided at least one end in said direction of said thermal spin-wave spin current generating material;
a heat source to give temperature gradient in said direction in said thermal spin-wave spin current generating material; and
a magnetic field generator to generate magnetic field in said direction in said thermal spin-wave spin current generating material,
wherein a thermal spin-wave spin current is converted to generate a voltage in said inverse spin-Hall effect material when there is a temperature gradient in said thermal spin-wave spin current generating material, and a magnetic field is applied using said magnetic field generator, and said thermoelectric conversion sub-elements are secured to a flexible substrate that is rolled up starting from the shortest inverse spin-Hall effect material so that adjacent inverse spin-Hall effect materials are connected in series.