| 摘要 |
PROBLEM TO BE SOLVED: To obtain a crystallized glass and a crystallized glass substrate having a high Young's modulus, a low melting temperature and a low liquid phase temperature and excellent in surface smoothness and to obtain an information recording disk such as a magnetic disk. SOLUTION: The crystallized glass for an information recording disk contains, by mol, 42-65% SiO2, 0-15% Al2O3, 5-30% MgO, 0.5-8% Y2O3 and >10 to 25% Li2O and has aβ-quartz solid solution and/or enstatite as the predominant crystal phase. The crystallized glass substrate for an information recording disk comprises the glass and the surface on which an information recording layer is formed has 0.1-0.9 nm surface roughness Ra. The information recording medium has the glass substrate and a recording layer formed on the glass substrate. The magnetic disk has the glass substrate and a magnetic recording layer formed on the glass substrate.
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