Patent ID: 6703332
Filing Date: 2004-03-09
Classification: C03C,G11B

Abstract:
A glass-ceramic for substrate of magnetic disk having high strength, wherein the glass-ceramic is of Li2Oâ€”SiO2â€”P2O5â€”Y2O3 system glass-ceramic and can be obtained by subjecting to heat treatment a base glass which consists essentially of in weight percent: from 65% to 80.0% of SiO2, from 0.5% to 5.0% of Al2O3, from 13.0% to 19.0% of Li2O, from 1.0% to 7.0% of P2O5, from 0.5% to 10.0% of Y2O3 and from 0.2% to 2.0% of at least one of Sb2O3 and As2O3, and the glass-ceramic comprises Li2OÂ·2SiO2 as the main crystal phase.