| 摘要 |
An optical information recording medium (100) of the present invention includes an information layer (011) that allows information to be recorded thereon and reproduced therefrom by irradiation with a laser beam (040). The information layer (011) includes a reflective layer (002), a first dielectric layer (003), a recording layer (005) capable of undergoing a phase change by the irradiation with the laser beam (040) and a second dielectric layer (007) formed in this order from a side opposite to a laser beam incident side. The recording layer (005) contains Ge, Sb and Te. When Ge, Sb and Te contained in the recording layer (005) are represented by GexSbyTez in atomic number ratio, x, y, and z satisfy 0.39@x@0.48, 0.02@y<0.11, 0.40@z<0.56, and x+y+z=1. The recording layer (005) has a thickness of at least 10 nm but not more than 15 nm. In the case where a ratio of an amount of reflected light of the laser beam (040) from the information layer (011) to an amount of the laser beam (040) incident on the information layer (011) is denoted as R (%), the R when the recording layer (005) is in a crystalline state is denoted as Rc (%), and the R when the recording layer (005) is in an amorphous state is denoted as Ra (%), Rc and Ra satisfy 6.0@Rc/Ra@12.0 and 1.0@Rc@3.0. |
