摘要 |
Disclosed is a process for preparation of crystallized glass obtained by making a glass containing TiO2 subjected to a phase separation step and a crystallization step, where the phase separation step has heat treatment of the glass at a temperature in a range from a temperature of the glass transition temperature Tg (Tg - 30 DEG C) to a temperature 60 DEG C higher than the glass transition temperature Tg (Tg + 60 DEG C). There are also disclosed a crystallized glass for information recording disk composed of the crystallized glass obtained by the preparation process, where a mean particle size of the crystal particles is in a range of equal to or less than 100 nm, or where a transparency at a wavelength of 600 nm is 40 % or higher; and an information recording disk, composed of the glass, having a polished surface with a surface roughness Ra (JIS B0601) in a range from 0.1 to 0.5 nm. <IMAGE> |