| 摘要 |
This glass substrate for information recording media is characterized by being formed of a glass composition which contains constituents that are within specific content ranges and satisfy the following conditions, in mol%, SiO2 + Al2O3 + B2O3 is 67-82%, Li2O + Na2O + K2O is 8-20% and MgO + CaO + SrO + BaO + ZnO is 10-28%, while being at ratios satisfying 0.85 ≤ SiO2/(SiO2 + Al2O3 + B2O3) ≤ 0.95, 0.3 ≤ Li2O/(Li2O + Na2O + K2O) ≤ 0.7 and 0.8 ≤ MgO/(MgO + CaO + SrO + BaO + ZnO) ≤ 0.99. |
