Compressibility of Binary Alkaline‐Earth Borate Glasses at High Pressures

Abstract

Compression data to 10,000 atm. were obtained for a series of barium, strontium, and calcium borate glasses at 21°C. The compressibility was found to be in the order Ba > Sr > Ca at corresponding molar concentrations and was not appreciably affected by pressure in the experimental pressure range. Comparison of data on alkali and alkaline‐earth borate glasses shows that the compressibility at corresponding molar concentrations is smaller in the alkaline‐earth glasses. Numerical comparisons at appropriate compositions show that a large part of the decreased compressibility produced by the alkaline‐earth oxides arises from electrovalent sources.