Specific Heats and Grüneisen Constant of Aluminosilicate Glasses Containing Rare-Earth Oxides

Rare-earth alumino-silicate glasses were prepared from Shirasu (volcanic ash) and yttria concentrate as the main starting materials. Specific heats and elastic constants of these glasses were measured at room temperature. Using these values and previously measured values of thermal expansion coefficients and densities, Gruneisen constants were calculated from the Gruneisen relation. There is a good linear relation between specific heat and chemical composition of these glasses containing about 20 oxides. Observed values of specific heat coincide with calculated values within 3% error. Observed bulk moduli were quite high (about 80 GPa). Values of the Gruneisen constant mainly depend on SiO2 content.