| 摘要 |
PURPOSE:To improve corrosion resistance and durability by incorporating silicon, aluminum and boron, >=1 kinds of bivalent metal elements, oxygen, and >=1 kinds among yttrium, lanthanoid element and actinoid element into a protective layer. CONSTITUTION:A magneto-optical recording medium 1 has the protective layer 31 on a substrate 2 and is provided with a thin magnetic film layer 4 as a recording layer thereon and a protective layer 35 on the rear face of the substrate. This protective layer 31 contains the silicon, the aluminum and/or the boron, >=1 kinds among the bivalent metal elements, the oxygen and >=1 kinds among the yttrium, lanthanoid element and actinoid element. The silicon, the aluminum and/or the boron, and >=1 kinds of the bivalent metal elements (M<2>) are incorporated in the form of ordinary oxides into the protective layer to form a glassy material in this case. The bivalent elements (M<2>) are exemplified by >=1 kinds among Ba, Ca, Mg, Zn, Pb, Sr, etc. Recording and reproducing characteristics such as recording sensitivity and C/N are thereby improved and the durability and corrosion resistance are improved as well. |
