informationsaufzeichnungstraeger and procedures to read / write information from the porter.

摘要

Disclosed is a rewritable information recording medium which has a recording layer (2) containing a Group I transition element and a Group IV typical element of the Periodic Table as two principal element and having the following characteristics, and a support substrate (1) for physically supporting the recording layer (2), and an information-write, -read, and -erase method, using this recording medium. When the recording layer (2) is immediately cooled after it is heated up to near a eutetic temperature of the two principal elements, two metastable phases having different energy levels appear. A state in the first metastable phase of the higher energy level has a reflectivity sufficiently higher than that of a state of a mixed phase including the second metastable phase of the lower energy level, or that of the equilibrium state. The state in the first metastable phase can be obtained by heating a recording layer (2) in another state by light beam irradiation. A portion (3) in the first metastable state is cooled after it is heated to a temperature lower than that for obtaining the first metastable phase, so that it can be converted to a state of the low reflectivity, i.e., a state of a mixed phase including the second metastable phase or to the equilibrium state. Since the recording layer can be reversibly altered between states of high and low reflectivities upon light beam irradiation, information can be erasably written. A write or erase-operation can be performed in a short period of time dur to the relationship between the crystal structures of the two states. Furthermore, the medium of this invention has no toxicity in terms of its constituents, and has good environmental resistance.