Heat capacity of pyrochlore Pr2Ru2O7

Abstract

Heat capacity measurements have been performed from 0.4to200K in 0T and from 0.4to20K in magnetic fields up to 9T on the cubic pyrochlore compound Pr2Ru2O7. The long-range antiferromagnetic ordering of the Ru4+ moments is accompanied by a sharp λ-type anomaly at 162K. At lower temperatures, there are two anomalies in the 0T data that are associated with the crystal electric field levels of Pr3+. While the broad shoulder around 40K can be attributed to the excitations to the first-excited singlet state, the Schottky-like peak at 2.6K suggests that the ground-state doublet is split by the lowering of crystal field symmetry. Detailed analysis of the Schottky-like anomaly suggests continuous distribution of the splitting, implying the presence of disorder in Pr2Ru2O7.