| 摘要 |
PURPOSE:To shorten the time for erasing and to improve storage property of records in an optical recording medium of phase transition type by adding a third metal to the medium film to increase the crystallization rate in a high temperature region and to lower the rate in a low temperature region. CONSTITUTION:The medium has the mean composition represented by Ge(x)Te(y)Cu(z), wherein the proportions of Ge (x mol%), Te (y mol%) and Cu (z mol%) satisfy formulae I, II and III. Addition of Cu to GeTe significantly increases the activation energy of the crystallization rate constant and the crystallization rate at high temp. On the other hand, the crystallization rate at low temp. decreases. |
