Heat Capacity of MnBr2 between 1.7 and 20°K. Magnetic Ordering in MnBr2

Abstract

The heat capacity of MnBr₂ has been measured between 1.7 and 20°K. The calorimeter and carbon resistance thermometer—heater are described. There is an anomaly in the heat capacity of MnBr₂, arising from the ordering of the spins of the manganous ions. The maximum heat capacity, in excess of 30 cal mole⁻¹ deg⁻¹, occurs at 2.16±0.01°K. The entropy associated with the magnetic ordering is R ln6 and the corresponding enthalpy is 10.84 cal mole⁻¹.