Substrate for information recording medium and magnetic recording medium composed of crystallized glass

摘要

Provided is a substrate for information recording medium composed of such a crystallized glass as having high Young's modulus, strength and heat resistance, being excellent in surface smoothness, surface homogeneity and surface processability, as well as having a relatively low temperature of glass liquid phase and being capable of producing cheaply, and an information recording medium using this substrate. The crystallized glass substrate for information recording medium comprising 35-65 mol % of SiO₂, 5-25 mol % of Al₂O₃, 10-40 mol % of MgO and 5-15 mol % of TiO₂, in which the total amount of aforementioned composition is at least equal to or higher than 92 mol % and the main crystals are enstatite and/or its solid solution. The information recording medium having this substrate and a recording layer formed on said substrate.