A thermoelectric conversion material formed of a sintered body containing magnesium silicide as a main component contains 0.5 mass % or more and 10 mass % or less of aluminum oxide. The aluminum oxide is distributed at a crystal grain boundary of the magnesium silicide.

A composite sintered body is a ceramic composite sintered body which includes metal oxide which is a main phase, and silicon carbide which is a sub-phase, in which crystal grains of the silicon carbide are dispersed in crystal grains of the metal oxide and at crystal grain boundaries of the metal oxide, and a proportion of the crystal grains of the silicon carbide dispersed in the crystal grains of the metal oxide is 25% or more in an area ratio with respect to a total crystal grains of the silicon carbide.

Highly dense lithium based ceramics can be prepared by a low temperature process including combining a lithium based ceramic with a polar solvent having a lithium based salt dissolved therein and applying pressure and heat to the combination to form a salt-ceramic composite. Advantageously, the lithium salt is one that dissolves in the polar solvent and the heat applied to the combination is no greater than about 250 C. Such composites can also have high ionic conductivity.

Provided is a piezoelectric ceramics including crystal grains each including: a first region that is formed of a perovskite-type metal oxide having a crystal structure in which a central element of a unit cell is located at an asymmetrical position; and a second region that is formed of a perovskite-type metal oxide having a crystal structure in which a central element of a unit cell is located at a symmetrical position, and that is present inside the first region, wherein a ratio of a cross-sectional area of the second region to a cross-sectional area of the piezoelectric ceramics is 0.1% or less.

Silicon particles for active materials and electro-chemical cells are provided. The active materials comprising silicon particles described herein can be utilized as an electrode material for a battery. In certain embodiments, the composite material includes greater than 0% and less than about 90% by weight of silicon particles. The silicon particles have an average particle size between about 0.1 ?m and about 30 ?m and a surface including nanometer-sized features. The composite material also includes greater than 0% and less than about 90% by weight of one or more types of carbon phases. At least one of the one or more types of carbon phases is a substantially continuous phase.

A solid electrolyte body for a gas sensor element constituted by solid electrolyte particles made of zirconia containing a stabilizer has a structure in which metal oxide particles are dispersed in a solid electrolyte phase in which a large number of the solid electrolyte particles are aggregated, and, in the solid electrolyte phase, pairs of the solid electrolyte particles adjoining each other do not have a grain boundary impurity layer between their particle interfaces, and the particle interfaces directly contact with each other.

A SiAlON sintered body according to the present invention is represented by Si.sub.6-zAl.sub.zO.sub.zN.sub.8-z (0<z4.2) and has an open porosity of 0.1% or less and a relative density of 99.9% or more. A ratio of a total of intensities of maximum peaks of components other than SiAlON to an intensity of a maximum peak of the SiAlON in an X-ray diffraction diagram is 0.005 or less.

A composite ceramic powder of the present invention includes: a LAS-based ceramic powder having precipitated therein -eucryptite or a -quartz solid solution as a main crystal; and TiO.sub.2 powder and/or ZrO.sub.2 powder,.

A body including a first phase having silicon carbide, a second phase comprising a metal oxide, the second phase being a discrete intergranular phase located at the grain boundaries of the first phase, and the body has an average strength of at least 700 MPa.

A multilayer electronic component includes a body including a capacitance forming portion including a dielectric layer and internal electrodes, and first to sixth surfaces; external electrodes disposed on the third and fourth surfaces of the body, respectively; and side margin portions disposed on the fifth and sixth surfaces of the body, respectively, wherein a Ba/Ti molar ratio of the side margin portion satisfies greater than 1.025 and less than 1.035, and is higher than a Ba/Ti molar ratio of the capacitance forming portion, wherein the number of moles of Mg based on 100 moles of Ti included in the side margin portion is greater than 1.0 mole and less than 2.0 moles, and wherein the number of moles of Sn based on 100 moles of Ti included in the side margin portion is 0.01 moles or more and less than 5.0 moles.