Glaskeramisches Trägermaterial hoher Steifigkeit für magnetisches Informationsaufzeichnungsmedium

摘要

A high rigidity glass-ceramic substrate for a magnetic information storage medium has a ratio of Young's modulus to specific gravity within a range from 37 to 63 and comprises Al2O3 within a range from 10% to less than 20%. Predominant crystal phases of the glass-ceramic substrate consist of (1) cordierite or cordierite solid solution and (2) one or more crystals selected from the group consisting of Spinel crystal, Spinel crystal solid solution, enstatite, enstatite solid solution, beta -quartz and beta -quartz solid solution.