Patent ID: 7994090

Claim:
A process for producing fine particles of a solid solution, comprising: obtaining a melt comprising, in terms of mol % on an oxide basis, from 5 to 50% ZrO 2 , CeO 2 and RE 2 O 3 where RE is at least one member selected from rare earth elements other than Ce in total, from 10 to 50% RO where R is Zn and optionally at least one member selected from the group consisting of Mg, Ca, Sr and Ba, and from 30 to 75% B 2 O 3 ; quenching the melt to obtain an amorphous material; heating the amorphous material to obtain precipitates comprising crystals of a solid solution comprising ZrO 2 , CeO 2 and RE 2 O 3 ; and separating the crystals of the solid solution from the precipitates to obtain fine particles of the solid solution.