Thermodynamic properties of silicides .4. Molar heat capacity at temperatures from 7K to 340 K and derived thermodynamic properties to T=2200 K of molybdenum disilicide (MoSi2.067+/-0.002)

The molar heal capacity of molybdenum disilicide MoSi2.067+/-0.002 was measured from T = 7 K to T = 340 K by adiabatic calorimetry. Our results show that no phase transition is present, but a slight anomaly was observed in the region of T = 200 K. From our results, the standard molar entropy Delta(0)(T)S(m) degrees(MoSi2.067+/-0.002,cr)/R = 7.394, where T = 298.15 K; on the basis of this result: the function Phi(m) degrees(MoSi2.067+/-0.002,cr,298.15 K)/R = 3.002. Heat capacities derived from transient heat-pulse calorimetry from T = 0.2 K to T = 7 K, and results from high-temperature adiabatic and drop calorimetry from T = 300 K to T = 2200 K, together with the heat capacities obtained in this work, allowed the estimation of thermodynamic functions to T = 2200 K. (C) 1996 Academic Press Limited