A transparent ceramic material is manufactured by molding a source powder into a compact, the source powder comprising a rare earth oxide consisting of at least 40 mol % of terbium oxide and the balance of another rare earth oxide, and a sintering aid, sintering the compact at a temperature T (1,300 C.T1,650 C.) by heating from room temperature to T1 (1200 C.T1T) at a rate of at least 100 C./h, and optionally heating from T1 at a rate of 1-95 C./h, and HIP treating the sintered compact at 1,300-1,650 C. The ceramic material has improved diffuse transmittance in the visible region and functions as a magneto-optical part in a broad visible to NIR region.

A composition including cerium and zirconium oxides, including at least 30 wt.-% cerium oxide is desired. Following calcination at a temperature of 900 DEG C. for 4 hours, the composition has two populations of pores, the diameters of the first population being centered around a value of between 5 nm and 15 nm for a composition including 30% to 65% cerium oxide or between 10 nm and 20 nm for more than 65% cerium oxide and the diameter of the second population being centered around a value of between 45 nm and 65 nm for 30% to 65% cerium oxide or between 60 nm and 100 nm for more than 65% cerium oxide.

A ceria composite particle dispersion has ceria composite particles having an average particle size of 50 to 350 nm and having the features described below. Each ceria composite particle has a mother particle, a cerium-containing silica layer on the surface thereof, and child particles dispersed inside the cerium-containing silica layer, the mother particles being amorphous silica-based and the child particles being crystalline ceria-based. The child particles have a coefficient of variation (CV value) in a particle size distribution of 14 to 40%. The ceria composite particles have a mass ratio of silica to ceria of 100:11-316. Only the crystal phase of ceria is detected when the ceria composite particles are subjected to X-ray diffraction. The average crystallite size of the crystalline ceria measured by subjecting the ceria composite particles to X-ray diffraction is 10 to 25 nm.

The invention relates to a composition containing zirconium, cerium and yttrium oxides with a cerium oxide proportion of between 3% and 15%, and yttrium oxide proportions corresponding to the following conditions: 6% at most if the cerium oxide proportion is between 12% excluded and 15% included; 10% at most if the cerium oxide proportion is between 7% excluded and 12% included; 30% at most if the cerium oxide proportion is between 3% and 7% included; the balance consisting of zirconium oxide. The composition may optionally include an oxide of a rare earth selected from lanthanum, neodymium and praseodymium. The composition can be used for processing the exhaust gases of a vehicle.

Disclosed here is a method for making a monolithic rare earth oxide (REO) aerogel, comprising: preparing a reaction mixture comprising at least one rare earth metal nitrate, at least one epoxide, at least one base catalyst, and at least one organic solvent; curing the mixture to produce a wet gel; drying the wet gel to produce a dry gel; and thermally annealing the dry gel to produce the monolithic REO aerogel. Also disclosed is an REO aerogel comprising a network of REO nanostructures, wherein the REO aerogel is a monolith having at least one lateral dimension of at least 1 cm, wherein the REO aerogel has a density of about 40-500 mg/cm.sup.3 and/or a BET surface area of at least about 20 m.sup.2/g, and wherein the REO aerogel is substantially free of oxychloride.

Disclosed here is a method for making a monolithic rare earth oxide (REO) aerogel, comprising: preparing a reaction mixture comprising at least one rare earth metal nitrate, at least one epoxide, at least one base catalyst, and at least one organic solvent; curing the mixture to produce a wet gel; drying the wet gel to produce a dry gel; and thermally annealing the dry gel to produce the monolithic REO aerogel. Also disclosed is an REO aerogel comprising a network of REO nanostructures, wherein the REO aerogel is a monolith having at least one lateral dimension of at least 1 cm, wherein the REO aerogel has a density of about 40-500 mg/cm.sup.3 and/or a BET surface area of at least about 20 m.sup.2/g, and wherein the REO aerogel is substantially free of oxychloride.

The present disclosure relates to a cathode material including bismuth-doped manganite-based perovskite and having excellent electrochemical properties and long-term stability, and a solid oxide fuel cell including the same. A cathode material according to an embodiment includes bismuth-doped manganite-based perovskite which is represented by Formula 1 below and in which praseodymium strontium manganite is deponed with bismuth:

##STR00001## wherein in the Formula 1, x is in a range of 0<X<0.5, and ? is in a range of 0<?<2.

The present disclosure relates to a cathode material including bismuth-doped manganite-based perovskite and having excellent electrochemical properties and long-term stability, and a solid oxide fuel cell including the same. A cathode material according to an embodiment includes bismuth-doped manganite-based perovskite which is represented by Formula 1 below and in which praseodymium strontium manganite is deponed with bismuth:

##STR00001## wherein in the Formula 1, x is in a range of 0<X<0.5, and ? is in a range of 0<?<2.

An oxide ion-conducting solid electrolyte is provided. The oxide ion-conducting solid electrolyte contains a mayenite-type compound having a representative composition represented by Ca.sub.12Al.sub.14O.sub.33, and at least one metal element M selected from lanthanum (La) and yttrium (Y), wherein the metal element M is contained in a range of from 0.4 mol % through 5.3 mol % in terms of an oxide relative to the whole of the oxide ion-conducting solid electrolyte.

In the piezoelectric film including a perovskite oxide which is represented by General Formula P, 0.1?x?0.3 and 0<y?0.49x are satisfied, A.sub.1+?[(Zr,Ti).sub.1-x-yNb.sub.xSc.sub.y]O.sub.z . . . General Formula P, in General Formula P, A is an A-site element primarily containing Pb, ?=0 and z=3 are standard values, but ? and z may deviate from standard values in a range in which a perovskite structure is capable of being obtained.