Heat capacity and thermodynamic functions of TiO2(H)

Abstract

The heat capacity of TiO2(H) has been measured in the temperature range of 1.9 K to 302 K. The experimental heat capacity is fitted using theoretical models, orthogonal polynomials and combination of Debye and Einstein function for the low, middle and high temperature range, respectively. Based on these fitted results, the standard molar heat capacity, entropy, enthalpy and Gibbs energy are calculated as (55.51 ± 0.56) J·K−1·mol−1, (50.55 ± 0.51) J·K−1·mol−1, (8.65 ± 0.09) kJ·mol−1, and –(6.42 ± 0.06) kJ·mol−1, respectively, at T = 298.15 K. Moreover, the heat capacity of TiO2(H) is similar to that of rutile and anatase, but significantly lower than those of brookite and TiO2(B) at temperature above 100 K.