Patent ID: 6569792
Filing Date: 2003-05-27
Classification: C03C,G11B

Abstract:
A crystallized glass substrate for information recording medium comprising SiO2 of 35 to 65 mol %, Al2O3 of 5 to 20 mol %, MgO of 10 to 40 mol %, and TiO2 of 5 to 15 mol %, wherein a mole ratio (Al2O3/MgO) is less than 0.5, the substrate comprising a primary crystal phase consisting essentially of a quartz solid solution and an enstatite, wherein the composition of the quartz solid solution is selected from the group consisting of 2MgO.2Al2O3.5SiO2, MgO.Al2O3.3SiO2, MgO.Al2O3.4SiO2 and mixtures thereof.