Heat Capacities and Thermodynamic Properties of the Iron Tellurides Fe1.11Te and FeTe2 from 5 to 350°K

Abstract

Heat capacities of the two iron telluride phases, Fe1.11 Te and FeTe2, were measured in the range 5 to 350°K. In Fe1.11Te a cooperative type of transformation was observed at about 63°K involving an entropy increment of 0.57 cal/mole °K. The thermodynamic functions were evaluated and the values of Cp, S°—S0°, and (H°—H0°)/T at 298.15°K are 13.15, 21.272, and 9.575 cal/mole °K, respectively, for Fe1.11Te, and the values of Cp, S°—S0°, H°—H0°, and — (F°—H0°)/T for FeTe2 are 17.60 and 23.940 cal/mole °K, 3567.4 cal/mole, and 11.975 cal/mole °K, respectively.