A thermoelectric material of the present invention includes copper, tin, and sulfur, wherein a ratio A/B of the number A of copper atoms to the number B of tin atoms is 0.5 to 2.5 and a content of a metal element other than copper and tin is 5 mol % or less with respect to total metal elements. Additionally, the thermoelectric material of the present invention has a thermal conductivity less than 1.0 W/(m.Math.K) at 200 to 400° C.

A solid composition according to the present disclosure is a solid composition to be used for forming a functional ceramic having a crystal phase, and contains an oxide constituted by a crystal phase different from the crystal phase of the functional ceramic at normal temperature and normal pressure, and an oxoacid compound. The oxoacid compound preferably contains at least one of a nitrate ion and a sulfate ion as an oxoanion. Further, the oxide preferably has a crystal grain size of 10 nm or more and 200 nm or less.

A ceramic powder material containing a garnet-type compound containing Li, wherein the ceramic powder material has a pore volume of 0.4 mL/g or more and 1.0 mL/g or less.

Provided herein is an electrically conductive, chemically insulated network of nanofibers that includes first carbon nanofibers electrically connected to second carbon nanofibers to form an electrically conductive network, and second carbon nanofibers electrically connected to other second carbon nanofibers, wherein at least one of the second carbon nanofibers is in direct surface contact with another of the second carbon nanofibers; and an active material that provides electrochemical insulation on surfaces of the first carbon nanofibers and partial surfaces of at least a portion of the second carbon nanofibers, wherein the active material comprises at least 50% by weight of the electrically conductive, chemically insulated network, and wherein the active material provides electrochemical insulation to the entirety of the electrically conductive, chemically insulated network of nanofibers including the area between the first carbon nanofibers and the second carbon nanofibers.

A precursor solution according to the present disclosure contains: an organic solvent; a lithium oxoacid salt that exhibits a solubility in the organic solvent; and a base metal compound that exhibits a solubility in the organic solvent and that is at least one base metal selected from the group consisting of Nb, Ta, and Sb.

Disclosed is a rapid, reproducible solution-based method to synthesize solid sodium ion-conductive materials. The method includes: (a) forming an aqueous mixture of (i) at least one sodium salt, and (ii) at least one metal oxide; (b) adding at least one phosphorous precursor as a neutralizing agent into the mixture; (c) concentrating the mixture to form a paste; (d) calcining or removing liquid from the paste to form a solid; and (e) sintering the solid at a high temperature to form a dense, non-porous, sodium ion-conductive material. Solid sodium ion-conductive materials have electrochemical applications, including use as solid electrolytes for batteries.

The present disclosure provides a glass ceramic composite electrolyte comprising gadolinium doped ceria and glass composite with desired ionic conductivity in the temperature range of 400 to 600° C., suitable for applications in solid oxide fuel cells. Also disclosed is a process for the preparation of the glass ceramic composite electrolyte.

Provided are a barium titanate-based piezoelectric ceramics having satisfactory piezoelectric performance and a satisfactory mechanical quality factor (Q.sub.m), and a piezoelectric element using the same. Specifically provided are a piezoelectric ceramics, including: crystal particles; and a grain boundary between the crystal particles, in which the crystal particles each include barium titanate having a perovskite-type structure and manganese at 0.04% by mass or more and 0.20% by mass or less in terms of a metal with respect to the barium titanate, and the grain boundary includes at least one compound selected from the group consisting of Ba.sub.4Ti.sub.12O.sub.27 and Ba.sub.6Ti.sub.17O.sub.40, and a piezoelectric element using the same.

A complex composite particle is made of a coal dust and binder composite that is pyrolyzed. Constituent portions of the composite react together causing the particles to increase in density and reduce in size during pyrolyzation, yielding a particle suitable for use as a proppant or in a composite structure.

The present invention relates to a mesoporous silica/ceria-silica composite and a method for preparing a mesoporous composite and, more specifically, to a mesoporous silica/ceria-silica composite which is composed of mesoporous silica having a hexagonal or cubic structure and ceria having a hexagonal structure provided on a surface and pores of the mesoporous silica, the oxidation state of the ceria being Ce.sup.4+ and Ce.sup.3+.