GLASS FOR MAGNETIC RECORDING MEDIUM SUBSTRATE, MAGNETIC RECORDING MEDIUM SUBSTRATE, MAGNETIC RECORDING MEDIUM, GLASS SPACER FOR MAGNETIC RECORDING/REPRODUCING DEVICE, AND MAGNETIC RECORDING/REPRODUCING DEVICE

摘要

Provided is a glass for a magnetic recording medium substrate, the glass being an amorphous oxide glass having an SiO₂ content of 56-80 mol%, an Li₂O content of 1-10 mol%, a B₂O₃ content of 0-4 mol%, a total content (MgO + CaO) of MgO and CaO of 9-40 mol%, a specific gravity of 2.75 g/cm³ or lower, a glass transition temperature of 650°C or higher, and a Young's modulus of 90 GPa or higher.