Crystallized glass substrate null SiO 2:42-65 mol

摘要

PROBLEM TO BE SOLVED: To provide a crystallized glass which has high Young's modulus, strength and heat resistance and excellent surface smoothness and surface homogeneity and which can be produced at a low cost for an information recording medium such as a magnetic disk. ;SOLUTION: The crystallized glass contains 42 to 65 mol% SiO2, 11 to 25 mol% Al2O3, 15 to 33 mol% MgO and 5.5 to 13 mol% TiO2, or 58 to 80 mol% of SiO2+Al2O3 and 0.125 to 0.55 ratio of MgO/(SiO2+Al2O3). Further, the main crystal or the crystal possessing ≥50 vol.% of the glass contains α-quartz solid solution or quartz-based crystal and enstatite and/or enstatite solid solution, or contains quartz-based crystal showing an almost equal diffraction pattern in the X-ray diffraction pattern to the diffraction pattern intrinsic to quartz and enstatite and/or enstatite solid solution. The crystal glass has ≥2.9 g/cm3 specific gravity.;COPYRIGHT: (C)2001,JPO