| 摘要 |
PROBLEM TO BE SOLVED: To provide a rare earth hydroxide that is slight in the change of rare earth element contents with time, contains little water of crystallization and little adhesive moisture and is easily dispersed in the base of ceramics. SOLUTION: The rare earth hydroxide is represented by the formula: Ln(OH)3 (where Ln is one or more rare earth elements selected from Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu), has <=40 nm particle diameter of crystallites measured by X-ray diffraction and contains <=300 ppm chlorine and <=100 pm nitrate ions. Loss on ignition at 1,000 deg.C for 1 hr is preferably <±2% of the theoretical value (%) and the average particle diameter of secondary particles obtained by the agglomeration of the crystallites is preferably 0.1-2 μm. |
