Abstract: A thermoelectric converter is made of a first thermoelectric conversion material in which at least one type of second thermoelectric conversion material particles having an average size of 1 to 100 nm is dispersed. At least a part of the second thermoelectric conversion material particles is dispersed at a distance not more than the mean free path of the phonons of the first thermoelectric conversion material.

Abstract: A nanocomposite thermoelectric conversion material capable of improving enhancement of ZT by reducing the thermal conductivity is provided by a production method for a nanocomposite thermoelectric conversion material composed of a matrix and a nanoparticle, the method comprising selecting the combination of at least three kinds of elements such that out of, one kind of an element becomes an oxide in the form of a nanoparticle; dissolving the elements such that the amount of the element constituting the nanoparticle becomes excessive with respect to the composition of the matrix in the final target product; adding a reducing agent to the solution, thereby allowing a reduction reaction to proceed at a plurality of different pH values from the initiation to the termination of reaction; and performing a hydrothermal treatment to cause formation of the matrix by alloying and formation of a nanoparticle composed of the oxide.

Abstract: A nanocomposite thermoelectric conversion material is provided in which crystal grains of a thermoelectric material parent phase are stacked in a laminar configuration and are oriented, the width of the crystal grains perpendicular to the direction of this orientation is in a range from at least 5 nm to less than 20 nm, and insulating nanoparticles are present dispersed at the grain boundaries. Also provided is a method of producing a nanocomposite thermoelectric conversion material, by which the crystal grains of a thermoelectric material parent phase are oriented by cooling a material under compression at a cooling rate of at least 1° C./minute to less than 20° C./minute. A thermoelectric conversion element that contains the aforementioned nanocomposite thermoelectric conversion material is also provided.

Abstract: A thermoelectric converter made of a thermoelectric conversion material is provided in which metal or alloy particles having an average particle size of 1 to 100 nm are dispersed, wherein at least a part of the metal or alloy particles are dispersed at a distance not more than the mean free path of the phonon of the thermoelectric conversion material.

Abstract: The invention provides a nanocomposite thermoelectric conversion material (1) in which the matrix has a polycrystalline structure, and crystal grains (10) and a crystal grain boundary phase (12) of a different composition are present therein, and in which the same type of phonon-scattering particles (14) are dispersed within the crystal grains (10) and the crystal grain boundary phase (12).

Abstract: A thermoelectric conversion material wherein at least a part of the insulating material contained in the thermoelectric conversion material has a particle size not larger than a mean free path of the phonons in the insulating material or wherein a dispersion gap of the insulating material is not larger than a mean free path of the phonons in the thermoelectric conversion material, and a method of producing the thermoelectric conversion material comprising the steps of forming composite nano particles by reducing and precipitating starting particles of a thermoelectric conversion material on the nano particles constituted by an insulating material, followed by a heat treatment to coat the nano particles with the thermoelectric conversion material; and packing and sintering the composite nano particles.

Abstract: A nanocomposite thermoelectric conversion material (100) includes a crystalline matrix (102) made of a thermoelectric conversion material; and phonon-scattering particles (108) dispersed in the crystalline matrix (102). Each phonon-scattering particle (108) includes at least one amorphous nanoparticle (106) coated with a crystalline film (104) having a nano-order thickness, and the crystalline structure of the crystalline film (104) is different from the crystalline structure of the thermoelectric conversion material.

Abstract: A method of producing a thermoelectric conversion element includes preparing a dispersion liquid by mixing slurry containing ceramic particles with salts of at least two elements that constitute a thermoelectric conversion material, and then, precipitating the at least two elements that constitute the thermoelectric conversion material on the ceramic particles in the dispersion liquid; performing washing; performing heating treatment; and performing sintering. Contact between a solution with a pH lower than 1 among solutions of the salts and the slurry containing the ceramic particles is avoided, or the solution with the pH lower than 1 contacts the slurry containing the ceramic particles for a first time when the at least two elements that constitute the thermoelectric conversion material are precipitated.

Abstract: A method of producing a nanocomposite thermoelectric conversion material includes preparing a solution that contains salts of a plurality of first elements constituting a thermoelectric conversion material, and a salt of a second element that has a redox potential lower than redox potentials of the first elements; precipitating the first elements, thereby producing a matrix-precursor that is a precursor of a matrix made of the thermoelectric conversion material, by adding a reducing agent to the solution; precipitating the second element in the matrix-precursor, thereby producing slurry containing the first elements and the second element, by further adding the reducing agent to the solution; and alloying the plurality of the first elements, thereby producing the matrix (70) made of the thermoelectric conversion material, and producing nano-sized phonon-scattering particles (80) including the second element, which are dispersed in the matrix (70), by filtering and washing the slurry, and then, heat-treating t

Abstract: A nanocomposite thermoelectric conversion material includes a matrix of the thermoelectric conversion material; and a dispersed material that is dispersed in the matrix of the thermoelectric conversion material, and that is in a form of nanoparticles. Roughness of an interface between the matrix of the thermoelectric conversion material and the nanoparticles of the dispersed material is equal to or larger than 0.1 nm.

Abstract: A thermoelectric converter made of a thermoelectric conversion material is provided in which metal or alloy particles having an average particle size of 1 to 100 nm are dispersed, wherein at least a part of the metal or alloy particles are dispersed at a distance not more than the mean free path of the phonon of the thermoelectric conversion material.

Abstract: A thermoelectric converter is made of a first thermoelectric conversion material in which at least one type of second thermoelectric conversion material particles having an average size of 1 to 100 nm is dispersed. At least a part of the second thermoelectric conversion material particles is dispersed at a distance not more than the mean free path of the phonons of the first thermoelectric conversion material.

Abstract: A method of manufacturing a thermoelectric converter is provided, wherein an alcohol dispersion liquid comprising a ceramic particle having the average size of 1 to 100 nm and a salt of an element constituting the thermoelectric conversion material is prepared, and thereafter the dispersion liquid is dropped into a solution containing a reducing agent to deposit a raw material particle of the thermoelectric conversion material, which is subsequently subject to heating and sintering.

Abstract: A thermoelectric conversion material wherein at least a part of the insulating material contained in the thermoelectric conversion material has a particle size not larger than a mean free path of the phonons in the insulating material or wherein a dispersion gap of the insulating material is not larger than a mean free path of the phonons in the thermoelectric conversion material, and a method of producing the thermoelectric conversion material comprising the steps of forming composite nano particles by reducing and precipitating starting particles of a thermoelectric conversion material on the nano particles constituted by an insulating material, followed by a heat treatment to coat the nano particles with the thermoelectric conversion material; and packing and sintering the composite nano particles.

Abstract: A method of producing a thermoelectric conversion element includes preparing a dispersion liquid by mixing slurry containing ceramic particles With salts of at least two elements that constitute a thermoelectric conversion material, and then, precipitating the at least two elements that constitute the thermoelectric conversion material on the ceramic particles in the dispersion liquid; performing washing; performing heating treatment; and performing sintering. Contact between a solution with a pH lower than 1 among solutions of the salts and the slurry containing the ceramic particles is avoided, or the solution with the pH lower than 1 contacts the slurry containing the ceramic particles for a first time when the at least two elements that constitute the thermoelectric conversion material are precipitated.