Abstract: A negative thermal expansion material including an oxide represented by one of the general formula (1) Cu2-xRxV2-yPyO7 (R includes at least one element selected from Mg, Al, Si, Ti, Cr, Mn, Fe, Co, Ni, Zn, and Sn, wherein 0?x?2, 0<y<2 are met), the general formula (2) Zn2-xTxP2-yAyO7 (T includes at least one element selected from Mg, Al, Si, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Ga, Ge, Zr, Nb, Mo, Ag, In, Sn, Sb, La, Ta, W, and Bi, A includes at least one element selected from Al, Si, V, Ge, and Sn, wherein O?x<2, 0?y?2 are met except that (x,y)=(0,0) and (0,2) are excluded), and the general formula (3) Ti2-xMxO3 (M includes at least one element selected from Mg, Al, Si, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Zr, Nb, Mo, Ag, In, Sn, Sb, La, Ta, W, and Bi, wherein O?x<2 is met) is provided.

Abstract: A thermoelectric conversion material according to an embodiment is expressed by the following formula (1): (M11-xM2x)4Si(Te1-yM3y)4 ??(1) wherein M1 represents Ta or Nb, M2 is at least one element selected from a group consisting of elements of groups 4 to 12 in the periodic table, M3 is at least one element selected from a group consisting of As, Sb, Bi, Sn and Pb, 0?x<0.02, 0?y<0.02, and M2 is an element different from M1 when 0<x.

Abstract: A ruthenium compound exhibits large negative thermal expansion. The ruthenium oxide is represented by the formula (1) Ca2?xRxRu1?yMyO4+z (wherein R represents at least one element selected from among alkaline earth metals and rare earth elements; M represents at least one element selected from among Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, and Ga; and the following relations are satisfied: 0?x<0.2, 0?y<0.3, and ?1<z<?0.02).

Abstract: A negative thermal expansion material according to an embodiment is represented by a general formula (1): Cu2-xRxV2O7 (R is at least one element selected from Zn, Ga, and Fe) and includes an oxide sintered compact whose linear expansion coefficient is ?10 ppm/K or less.

Abstract: A thermoelectric conversion material according to an embodiment is expressed by the following formula (1): (M11-xM2x)4Si(Te1-yM3y)4 ??(1) wherein M1 represents Ta or Nb, M2 is at least one element selected from a group consisting of elements of groups 4 to 12 in the periodic table, M3 is at least one element selected from a group consisting of As, Sb, Bi, Sn and Pb, 0?x<0.02, 0?y<0.02, and M2 is an element different from M1 when 0<x.

Abstract: A composite material of one aspect includes a resin matrix phase, and a ruthenium oxide having Ca2RuO4 structure and included in the resin matrix phase. The ruthenium oxide may be represented by a general formula (1): Ca2?xRxRu1?y1MyO4+z, in which R may represent at least one element selected from among alkaline earth metals and rare earth elements, M may represent at least one element selected from among Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, and Ga, and the values x, y, and z may satisfy 0?x<0.2, 0?y<0.3, and ?1<z<?0.02.

Abstract: A ruthenium compound exhibits large negative thermal expansion. The ruthenium oxide is represented by the formula (1) Ca2?xRxRu1?yMyO4+z (wherein R represents at least one element selected from among alkaline earth metals and rare earth elements; M represents at least one element selected from among Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, and Ga; and the following relations are satisfied: 0?x<0.2, 0?y<0.3, and ?1<z<?0.02).

Abstract: Provided is a thermal expansion inhibitor which has a much broader application range and which can be used with ease. Used is a thermal expansion inhibitor comprising a manganese nitride crystal.

Abstract: Provided is a thermal expansion inhibitor which has a much broader application range and which can be used with ease. Used is a thermal expansion inhibitor comprising a manganese nitride crystal.