Antiferromagnetic transition in dysprosium dihydride low-temperature heat capacity studies

The low temperature specific heats of dysprosium dihydride, DyH1.99, were measured in the range 1.8 to 22 K. Two specific heat anomalies were found: one sharp λ-type anomaly at TN = (3.30 ± 0.03) K and a rather broad second one at Tc = (4.5 ± 0.1) K. The first anomaly is interpreted as due to an antiferromagnetic transition in DyH1.99. The reason for the occurrence of the second anomaly is not clear as yet. The entropy change due to the magnetic contributions to the specific heat has been evaluated and interpreted.