| 摘要 |
PROBLEM TO BE SOLVED: To suppress the increase of jitters caused by the increase of overwriting times by preparing a compsn. containing a specified range of silicon dioxide, a specified range of one or more elements selected from Pr, Nd, Sm, Gd, Eu, Pm, Tb, Dy, Ho, Er, Tm, Yb and Lu in total, and the balance of zinc sulfide. SOLUTION: This dielectric film for a optical recording medium has a compsn. containing 10 to 30 mol.% of silicon dioxide, 0.001 to 5 mol% in total (A) of one ore more elements selected from Pr, Nd, Sm, Gd, Eu, Pm, Tb, Dy, Ho, Er, Tm, Yb and Lu, and the balance of zinc sulfide. The film is produced by adding silicon dioxide powder and (A) to zinc sulfide powder which is preliminarily heated in an Ar atmosphere to degas, homogeneously mixing in a dry state, keeping the obtd. mixture powder in vacuum or an Ar gas atmosphere at specified pressure and temp. for a specified time, cooling to obtain a sintered body, grinding the sintered body and then sputtering. |
