Calculation of the heat capacity of oxide glasses at temperatures from 100 K to the lower boundary of glass transition range

Abstract

A method for calculating the heat capacity of oxide glasses from the data on their composition and temperature has been proposed. Thirty two oxides are included in calculations. A new empirical equation that describes the temperature dependence of the heat capacity is used in the calculations. This equation makes it possible to interpolate the experimental data over a wide range of temperatures (from 100 K to the lower boundary of the glass transition range) and involves only one fitting parameter. The atomic additive formula is applied to the calculation of the heat capacity from the glass composition. The results of calculations are compared with the data available in the literature on the heat capacity for ∼500 glasses with the use of the SciGlass information system describing the glass properties. The root-mean-square deviations of the calculated data from the experimental results are equal to 5–7%. The method proposed is highly competitive in accuracy with the known techniques for calculating the heat capacity of glasses and allows one to extend considerably the composition and temperature ranges covered.