Low-temperature heat capacities of molybdenum diselenide and ditelluride

Abstract

The low-temperature heat capacities of MoSe2 and MoTe2 have been determined for technological and scientific reasons. Both compounds in their hexagonal form have a lamellar sandwich-layer structure and in confirmation of extant data on molybdenite, MoS2, these compounds are shown to follow the Debye limiting law for heat capacity at low temperature despite contrary indications in the literature. At 298.15 K the heat capacity Cp, entropy So, and Gibbs energy in the form {Go(T) - Ho(0)}/T are(for MoSe2) 16.87, 21.29, and -10.33 calth K-1 mol-1; and (for MoTe2) 18.38, 27.55, and -14.60 calth K-1 mol-1.