US Patent 7709073 Information recording medium

In an information recording medium on and from which information is recorded and reproduced by applying light or electric energy, a recording layer which generates reversible phase change is formed so as to include a material containing Ge, Bi, Te and an element “M” which material is expressed with (GeTe)x[(M2Te3)y(Bi2Te3)1-y]100-x (mol %) wherein “M” represents at least one element selected from Al, Ga and In, and “x” and “y” satisfy 80≦x<100 and 0<y≦0.9, whereby the medium is obtained which ensures a high erasability and an excellent archival characteristic at a high linear velocity and in a wide range of linear velocities.