据日立制作所声称,该所在世界上首先研制成一种通过光之类的热能使材料的色调进行可逆变化的金属新材料“光记录合金”。这种合金具有下述性质:在室温下呈银白色,加热到300℃以上后聚冷就变成粉红色,室温时间保持粉红色;再加热到100～300℃时便还原成原来的银白色。该新材料是银-锌、银-铝-铜之类的二元或三元的新功能材料。 According to Hitachi, it claims the world first developed a “new optical recording material” that reversibly changes the color tone of materials through the use of thermal energy such as light. This alloy has the following properties: silver white at room temperature, heated to 300 ℃ above the poly-cold becomes pink, pink at room temperature time; then heated to 100 ~ 300 ℃ will be reduced to the original silver-white . The new material is a binary or ternary new functional material such as silver-zinc, silver-aluminum-copper.