Reflection layer for highly durable optical information recording media, contains silver group alloy containing preset amount of element(s) chosen from copper, neodymium, tin and germanium and rare earth element(s)

摘要

Reflection layer (4) or a semitransparent reflection layer (2) for highly durable optical information recording media, contains silver group alloy. The silver group alloy contains at least one kind of element chosen from 0.5% or more of copper, and 0.5-3% of neodymium, tin and germanium, and 0.1% or more of at least one kind or rare earth element. Independent claims are also included for the following: (a) Optical information recording medium; (b) Sputtering target for optical information recording medium