A novel process provides for the preparation of the chlorinated, uncharged substance tetrakis(trichlorosilyl)germane, and for the use thereof.

A novel process provides for the preparation of the chlorinated, uncharged substance tetrakis(trichlorosilyl)germane, and for the use thereof.

A thermoelectric conversion material includes: a base material that is a semiconductor; and an additive element that differs from an element constituting the base material. An additional band formed of the additive element is present within a forbidden band of the base material. A density of states of the additional band has a ratio of greater than or equal to 0.1 relative to a maximum value of a density of states of a valence band adjacent to the forbidden band of the base material.

A thermoelectric conversion material includes: a base material that is a semiconductor; and an additive element that differs from an element constituting the base material. An additional band formed of the additive element is present within a forbidden band of the base material. A density of states of the additional band has a ratio of greater than or equal to 0.1 relative to a maximum value of a density of states of a valence band adjacent to the forbidden band of the base material.

A magnesium-based thermoelectric conversion material made of a sintered compact of a magnesium compound, in which, in a cross section of the sintered compact, a Si-rich metallic phase having a higher Si concentration than in magnesium compound grains is unevenly distributed in a crystal grain boundary between the magnesium compound grains, an area ratio of the Si-rich metallic phase is in a range of 2.5% or more and 10% or less, and a number density of the Si-rich metallic phase having an area of 1 μm.sup.2 or more is in a range of 1,800/mm.sup.2 or more and 14,000/mm.sup.2 or less.

A semiconductor sintered body comprising a polycrystalline body, wherein the polycrystalline body comprises magnesium silicide or an alloy containing magnesium silicide, and the average grain size of the crystal grains constituting the polycrystalline body is 1 μm or less, and the electrical conductivity is 10,000 S/m or higher.

A semiconductor sintered body comprising a polycrystalline body, wherein the polycrystalline body comprises magnesium silicide or an alloy containing magnesium silicide, and the average grain size of the crystal grains constituting the polycrystalline body is 1 μm or less, and the electrical conductivity is 10,000 S/m or higher.

A thermoelectric conversion material consists of a non-doped sintered body of a magnesium-based compound, in which an electric resistance value is 1.0×10.sup.−4 Ω.Math.m or less. The magnesium-based compound is preferably one or more selected from a MgSi-based compound, a MgSn-based compound, a MgSiSn-based compound, and a MgSiGe-based compound.

A thermoelectric conversion material consists of a non-doped sintered body of a magnesium-based compound, in which an electric resistance value is 1.0×10.sup.−4 Ω.Math.m or less. The magnesium-based compound is preferably one or more selected from a MgSi-based compound, a MgSn-based compound, a MgSiSn-based compound, and a MgSiGe-based compound.

A plate-shaped thermoelectric conversion material having a first main surface and a second main surface on the opposite side of the first main surface is formed of semiconductor grains that are in contact with one another. The semiconductor grains each include a particle composed of a semiconductor containing an amorphous phase, and an oxidized layer covering the particle. The distance between the first main surface and the second main surface exceeds 0.5 mm.