Hitachi, Ltd.

Hitachi Metals, Ltd.

Tohoku University

Yosuke Kurosaki

Shin Yabuuchi

Akinori Nishide

Jun Hayakawa

Jyun Hayakawa

Naoto Fukatani

Hiroyuki Yamamoto

Hideo Ohno

Shoji Ikeda

Katsuya Miura

Yuji Suwa

Masakuni Okamoto

Yuzuru Miyazaki

Tomohisa Takamatsu

Kei Hayashi

Shin Yabuchi

The present invention improves the performance of a thermoelectric conversion material and a thermoelectric conversion module. A thermoelectric conversion material has a mother phase containing a chimney ladder type compound comprising a first element of groups 4 to 9 and a second element of groups 13 to 15 and an additive phase existing at a grain boundary of the mother phase, the mother phase contains a third element to change a lattice constant of the chimney ladder type compound, and the additive phase contains the second element.

Thermoelectric conversion material and thermoelectric conversion module

Provided are a p-type thermoelectric conversion material, a thermoelectric conversion module, and a method of manufacturing a p-type thermoelectric conversion material that are capable of obtaining high thermoelectric conversion characteristics. The p-type thermoelectric conversion material has a full Heusler alloy having a composition represented by the following General Formula (1) and has a relative density of 85% or more, FeTiMAMB. . . (1), wherein in Formula (1), MA is one element selected from the group consisting of Si, Sn, and Ge, MB is one element selected from the group consisting of Al, Ga, and In, and x, y, a, and b are numbers set so that x+y+a+b=100, a+b=z, 50&#x3c;x&#x2264;52.5, 20&#x2264;y&#x2264;24.5, 24.5&#x2264;z&#x2264;29, a&#x3e;0, and b&#x3e;0 in atom %, respectively.

P-type thermoelectric conversion material, thermoelectric conversion module, and method of manufacturing p-type thermoelectric conversion material

In order to provide an Fe2TiSi type full-Heusler thermoelectric conversion material having a high dimensionless figure-of-merit ZT, the full-Heusler thermoelectric conversion material is characterized in that: the full-Heusler thermoelectric conversion material has secondary crystal grains having an Fe2TiSi type composition and a coating layer covering the circumference of the secondary crystal grains and containing an element other than Fe, Ti, and Si as a main component; and the coating layer has a composition containing an element being dissolvable in a crystal structure of the Fe2TiSi type composition and having an electric resistivity lower than the secondary crystal grains.

Thermoelectric conversion material, method for producing same, and thermoelectric conversion module

Provided is a thermoelectric conversion material formed from a full Heusler alloy represented by the composition formula: Fe(TiM1)(AlM2). M1 represents at least one element selected from the group consisting of V, Nb and Ta, and M2 represents at least one element selected from the group consisting of Group 13 elements except for Al and Group 14 elements. &#x3b1; satisfies the relation: 0&#x3c;&#x3b1;&#x2264;0.42, &#x3b2; satisfies the relation: 0&#x2264;&#x3b2;&#x3c;0.75, and &#x3b4; satisfies the relation: 0&#x2264;&#x3b4;&#x3c;0.5. The valence electron concentration, VEC, satisfies the relation: 5.91&#x2264;VEC&#x3c;6.16.

Thermoelectric conversion material

A thermoelectric conversion material includes a matrix phase configured from a semiconductor. A first grain-boundary phase and a second grain-boundary phase are provided at a grain boundary of the matrix phase. The first grain-boundary phase is configured from a material which does not form a compound with the matrix phase by a eutectic reaction, a eutectoid reaction, a peritectic reaction, a peritectoid reaction, an eccentric reaction, or a segregation reaction. The second grain-boundary phase is configured from a material having resistance which is lower than that of the matrix phase or the first grain-boundary phase. A ratio of a volume of the second grain-boundary phase to a volume of the first grain-boundary phase is smaller than 1.

The present invention aims at providing a thermoelectric conversion module with low toxicity, which exhibits conversion efficiency equivalent to that of BiTe. The thermoelectric conversion module of the present invention employs a full Heusler alloy as the material for forming the P-type thermoelectric conversion unit and the N-type thermoelectric conversion unit. The material for forming the N-type thermoelectric conversion unit contains at least any one of Fe, Ti, and Si and Sn.

Thermoelectric conversion module

Provided is a thermoelectric conversion element having a greater Seebeck coefficient (S) than the conventional ones. In a thermoelectric conversion element: a nonmagnetic Heusler alloy film (), a ferromagnetic Heusler alloy film () and a nonmagnetic layer () are stacked in the named order; a pair of electrodes () are disposed for deriving, in accordance with a temperature gradient occurring in parallel to the direction of magnetization () of the ferromagnetic Heusler alloy film, an electromotive force occurring perpendicularly to the direction of magnetization of the ferromagnetic Heusler alloy film; a pair of electrodes () are disposed for deriving an electromotive force occurring in parallel to the direction of magnetization of the ferromagnetic Heusler alloy film; and the electromotive forces occurring due to an ordinary Seebeck effect and a spin Seebeck effect are simultaneously derived.

Thermoelectric conversion element and thermoelectric conversion module using same

In order to provide a thermoelectric conversion element which has a high Seebeck coefficient, a low thermal conductivity, and a high performance, even if the material system that has a low environmental load and can reduce the cost is used, the thermoelectric conversion element in which lattice points are classified into two or more kinds (A site and B site), lattices of which the kinds are different are connected to each other, the numbers of lattices of which the kinds are different are different (A site: 2, and B site: 1), and a lattice structure is configured by arranging nanoparticles or semiconductor quantum dots, includes areas of which conductivity types are different.

Thermoelectric conversion element and thermoelectric conversion module

A thermoelectric conversion device includes a Heusler alloy film having a structure of Bor Lin notation of ABC and a pair of electrodes on the Heusler alloy film to output an electromotive force generated by a thermal gradient in the Heusler alloy film. The thermoelectric conversion device further includes an electrode for applying an electric field or a voltage to the Heusler alloy film to increase and control an electric conductivity and a Seebeck coefficient S of the Heusler metal film. The device can control to increase an electric conductivity and Seebeck coefficient S by applying an electric field or a voltage through an insulation film to the Heusler alloy film. The device may have a shared connection to select one of outputs of a plurality of thermoelectric conversion devices arranged in a matrix or increase an electromotive force as an output.

Thermoelectric conversion device

Provided is a tunnel magnetoresistive effect element such that a high TMR ratio and a low write current can be realized, and the thermal stability factor (E/kT) of a recording layer and a pinned layer is increased while an increase in resistance of the element as a whole is suppressed, thus enabling a stable operation. On at least one of a recording layerand a pinned layereach comprising CoFeB, electrically conductive oxide layersandare disposed on a side opposite to a tunnel barrier layer

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Tokyo, Japan

Yosuke Kurosaki