GLASS FOR MAGNETIC RECORDING MEDIUM SUBSTRATE OR FOR GLASS SPACER TO BE USED IN MAGNETIC RECORDING/REPRODUCING DEVICE, MAGNETIC RECORDING MEDIUM SUBSTRATE, MAGNETIC RECORDING MEDIUM, GLASS SPACER TO BE USED IN MAGNETIC RECORDING/REPRODUCING DEVICE, AND MAGNETIC RECORDING/REPRODUCING DEVICE

摘要

Provided is a glass which is for a magnetic recording medium substrate or for a glass spacer to be used in a magnetic recording/reproducing device and in which: the total content (Li₂O+Na₂O+K₂O+B₂O₃+ZnO) of Li₂O, Na₂O, K₂O, B₂O₃, and ZnO is 0-3 mol%; the mole ratio [(Al₂O₃+MgO)/(SiO₂+CaO)] of the total content of Al₂O₃ and MgO with respect to the total content of SiO₂ and CaO is 0.30-0.6; the total content (SiO₂+Al₂O₃) of SiO₂ and Al₂O₃ is 64-85 mol%; and the total content (SiO₂+Al₂O₃+MgO+CaO) of SiO₂, Al₂O₃, MgO, and CaO is 87-98 mol%.