A solid electrolyte, in which a part of an element contained in a mobile ion-containing material is substituted, and an occupied impurity level that is occupied by electrons or an unoccupied impurity level that is not occupied by electrons is provided between a valence electron band and a conduction band of the mobile ion-containing material, and a smaller energy difference out of an energy difference between a highest level of energy in the occupied impurity level and an energy and a LUMO level difference between a lowest level of energy in the unoccupied impurity level and a HOMO level is greater than 0.3 eV.

A paramagnetic garnet-type transparent ceramic is a sintered body of complex oxide represented by the following formula (1), comprising SiO.sub.2 as a sintering aid in an amount of more than 0% by weight to 0.1% by weight or less, and has a linear transmittance of 83.5% or more at the wavelength of 1,064 nm for an optical path length of 25 mm:
(Tb.sub.1-x-yY.sub.xSc.sub.y).sub.3(Al.sub.1-zSc.sub.z).sub.5O.sub.12  (1)
wherein 0.05≤x<0.45, 0<y<0.1, 0.5<1−x−y<0.95, and 0.004<z<0.2.

A method of preparing a lithium-ion conducting garnet via low-temperature solid-state synthesis is disclosed. The lithium-ion conducting garnet comprises a substantially phase pure aluminum-doped cubic lithium lanthanum zirconate (Li.sub.7La.sub.3Zr.sub.2O.sub.14). The method includes preparing nanoparticles comprising lanthanum zirconate (La.sub.2Zr.sub.2O.sub.7-np) via pyrolysis-mediated reaction of lanthanum nitrate (La(NO.sub.3).sub.3) and zirconium nitrate (Zr(NO.sub.3).sub.4). The method also includes pyrolyzing a solid-state mixture comprising the La.sub.2Zr.sub.2O.sub.7-np, lithium nitrate (LiNO.sub.3), and aluminum nitrate (Al(NO.sub.3).sub.3) to give the Li.sub.7La.sub.3Zr.sub.2O.sub.14 and thereby prepare the lithium-ion conducting garnet. A lithium-ion conducting garnet prepared via the method is also disclosed.

Disclosed herein is a sintered ceramic body comprising from 90% to 99.9% by volume of polycrystalline yttrium aluminum garnet (YAG) as measured using XRD and image processing methods and a volumetric porosity of from 0.1 to 4% as calculated from density measurements performed in accordance with ASTM B962-17. The sintered ceramic body may have a total purity of 99.99% and greater and a grain size of from 0.3 to 8 μm. A method of making the sintered ceramic body is also disclosed.

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.

A YAG ceramic bonded body in which a YAG ceramic and a YAG ceramic or optical glass are bonded, wherein the YAG ceramic bonded body comprises glass as a bonding layer, and has a rate of change of transmittance that is within 7%. An object of this invention is to provide a bonded body in which a YAG ceramic and a YAG ceramic are bonded, or a bonded body in which a YAG ceramic and optical glass are bonded, and which is capable of suppressing the reflection of light at the bonded interface, as well as the production method thereof.

A solid electrolyte which contains a garnet-type composite metal oxide phase (L) and shows an excellent lithium ion conductivity is provided. The solid electrolyte contains a garnet-type composite metal oxide phase (L) and a phase (D) different from the phase (L). The phase (L) contains Li, La, Zr, O, and Ga, and an Li site in the phase (L) is substituted with the Ga. A lattice constant of the solid electrolyte is not smaller than 12.96 Å. The phase (D) contains at least one of LiF, BaZrO.sub.3, YF.sub.3, SrF.sub.2, and ScF.sub.3.

The sintered body has an average particle size in the range of 0.1 μm or more and 5 μm or less, includes gamet-type oxide base material particles having at least Li, La, and Zr, has 8% by volume or more of voids, and has an ionic conductivity of 1.0×10.sup.−5 S/cm or more at temperature of 25° C.

A method for producing a ceramic composite includes: preparing a sintered body in a plate form containing a fluorescent material having a composition of a rare earth aluminate, and aluminum oxide; and eluting the aluminum oxide from the sintered body by contacting the sintered body with a basic substance, for example, contained in an alkali aqueous solution, and the dissolution amount of the fluorescent material eluted from the sintered body in the step of eluting the aluminum oxide is 0.5% by mass or less based on an amount of the fluorescent material contained in the sintered body as 100% by mass.

A method includes molding a raw material powder containing a ceramic powder and a thermoplastic resin having a glass transition temperature higher than room temperature into a shape by isostatic pressing and in which a raw material powder slurry is prepared by adding the ceramic powder and the thermoplastic resin to a solvent so that the thermoplastic resin is 2% by weight or more and 40% by weight or less with respect to a total weight of the ceramic powder and the thermoplastic resin, a cast-molded body is to formed by wet-casting the raw material powder slurry into a shape, dried, and subjected to first-stage isostatic press molding at a temperature lower than the glass transition temperature of the thermoplastic resin, then this first-stage press-molded body is heated to the glass transition temperature of the thermoplastic resin or above, and warm isostatic press (WIP) molding is performed.