| 摘要 |
PURPOSE:To obtain an optical information recording member superior in heat resistance, humidity resistance, recording properties, and erasing properties, by providing a thin film which is mainly made of Te, Ge, Se, and Pb with a specific ratio of number of atoms of Te, Ge, and Se and a specific value of density of Pb. CONSTITUTION:A recording layer is a composition of a Te-Ge-Se-Pb series, and in a material of the recording layer, the ratio of number of atoms of Te, Ge, and Se is within the area connecting the points A1, B1, C1, D1, and E1 and the density of Pb is 10-35atom%. An excess Te is fixed as a Pe-Te by adding Pb to a Te-Ge-Se series of high crystallization transition point temperature. Namely, Ge and Pb form compounds of GeTe and PbTe, and the effect of the compounds results in the enhanced speed of crystallization. In the Pb-Te series of 50% or more Te density, the maximum melting point is as high as 917 deg.C. This value is higher than that of the other Te-Ge compound, but it can be considered that the effect of Se lowers the melting point of the film. Therefore, addition of Pb slightly arises the melting point of the film containing Te as a base material, however, a sufficient non-crystallization is made possible by using a semiconductor laser. In this manner, addition of Pb improves the speed of crystallization, thus obtaining a recording film of capable of rewriting. |
