摘要 |
A glass ceramics composition for recording disk substrate contains, essentially, expressed in terms of weight percent on the oxide basis, from 47.5 to 52.5 wt % of SiO2, from 10 to 30 wt % of Al2O3, from 10 to 30 wt % of MgO, and from 6.2 to 7.8 wt % of TiO2.
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