This document describes processes for preparing ceramics, especially lithium-based ceramics. The ceramics produced by this process and their use in electrochemical applications are also described as well as electrode materials, electrodes, electrolyte compositions, and electrochemical cells comprising them.

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.

Disclosed is a scandia-stabilized zirconia electrolyte for a solid oxide fuel cell, which is configured such that at least one oxide selected from among gadolinium oxide (Gd.sub.2O.sub.3) and samarium oxide (Sm.sub.2O.sub.3) is co-doped with ytterbium oxide (Yb.sub.2O.sub.3) to thus improve stability in a reducing atmosphere. The scandia-stabilized zirconia electrolyte of the invention can be stabilized into a cubic crystal structure at room temperature while retaining the inherently high oxygen ionic conductivity of a scandia-stabilized zirconia electrolyte (11ScSZ), and can also ensure stability in a reducing atmosphere by solving the problem with a conventional ceria (CeO.sub.2)-doped scandia-stabilized zirconia in which the ionic conductivity continuously deteriorates in a reducing atmosphere.

Translucency of a yttria-stabilized zirconia ceramic is improved to achieve even higher translucency than what is currently offered on the market, without greatly altering its mechanical properties. The enhancement is done by incorporating magnesium-containing dopants into the microstructure of yttria-stabilized zirconia ceramic dental ceramics.

A cBN sintered material comprising cBN particles and a binder phase, in which the binder phase contains AlN and AlB.sub.2, a content proportion of cBN particles is 70 to 97 vol %, cBN sintered material has a volume resistivity up to 5×10.sup.−3 Ωcm, a rate of a peak intensity derived from Al with respect to a peak intensity derived from cBN particles is less than 1.0%, cBN particles include fine particles and coarse particles, coarse particles optionally include ultra-coarse particles, with respect to the entire cBN particles, a content proportion α of fine particles is from 10 vol %, a content proportion β of coarse particles is from 30 vol %, a content proportion γ of ultra-coarse particles is 25 vol % or less, and a total of the content proportion α of fine particles and the content proportion β of coarse particles is 50 to 100 vol %.

Provided is a zirconia sintered body having both high translucency and high strength. The zirconia sintered body includes crystal grains that include a cubic domain and a tetragonal domain, wherein a stabilizer and lanthanum is dissolved as a solid solution therein. The sintered body can be obtained by a manufacturing method including: a mixing step of obtaining a mixed powder by mixing a zirconia source, a stabilizer source, and a lanthanum source; a molding step of obtaining a green body by molding the obtained mixed powder; a sintering step of obtaining a sintered body by sintering the obtained green body at a sintering temperature of 1650° C. or higher; and a temperature lowering step of lowering the temperature from the sintering temperature to 1000° C. at a temperature lowering rate exceeding 1° C./min.

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+.

A sintered body including zirconia containing a stabilizer, wherein the sintered body has a monoclinic fraction of 0.5% or more and has a three-point bending strength of more than 1450 MPa as measured by a three-point bending test according to JIS R 1601. - - -

A composite ceramic including: a lithium garnet major phase; and a grain growth inhibitor minor phase, as defined herein. Also disclosed is a method of making composite ceramic, pellets and tapes thereof, a solid electrolyte, and an electrochemical device including the solid electrolyte, as defined herein.

A solid oxide fuel cell (SOFC) includes a cathode electrode, a solid oxide electrolyte, and an anode electrode. The electrolyte and/or electrode composition includes zirconia stabilized with (i) scandia, (ii) ceria, and (iii) at least one of yttria and ytterbia. The composition does not experience a degradation of ionic conductivity of greater than 15% after 4000 hrs at a temperature of 850° C.