Patent ID: 6858277

Claim:
An information recording medium comprising a substrate and a recording material layer formed on the substrate, the recording material layer undergoing reversible phase change between electrically or optically detectable states by electric energy or by electromagnetic energy, wherein the recording material layer comprises a material selected from a material ‘A’ having a crystal structure comprising a lattice defect in one phase of the reversible phase change; or a material ‘B’ in a complex phase composed of a crystal portion comprising a lattice defect and an amorphous portion in one phase of the reversible phase change, and the crystal portion and the amorphous portion comprise a common element; at least a part of the lattice defect is filled with an element other than an element constituting the crystal structure, the crystal structure comprising the lattice defect comprises Ge, Sb and Te, the crystal structure comprising the lattice defect further comprises at least one element selected from Sn, Cr, Mn, Ag, Al, Pb, In and Se, and the crystal structure comprising the lattice defect further comprises at least one combination of elements selected from Sn—Cr, Sn—Mn, Sn—An, Mn—Ag, Cr—Ag, Sn—Mn, and Sn—Cr—Ag.