Heat Capacity of Tm2(SO4)3·8H2 O between 0.08 and 20 K

Abstract

The heat capacity of ${\mathrm{Tm}}_2$ ${\left(\mathrm{S}{\mathrm{O}}_4\right)}_3$·8${\mathrm{H}}_2$O shows a sharp peak, characteristic of a cooperative transition, superimposed on the low-temperature side of the anomaly associated with the singlet ground and first excited states. The data are in qualitative agreement with theory for exchange-induced magnetization in a singlet-crystal-field-ground-state system.