Heat capacity and thermal expansion of CdCr2Se4 and CdCr2S4

The thermodynamic properties of the spinel ferromagnetic compounds CdCr2Se4 and CdCr2S4 have been investigated by making heat capacity and thermal expansion measurements on single crystals. For both compounds, the ferromagnetic transition is marked by λλ-type thermal anomalies, and the results provide a pressure dependence of the transition temperatures that is in agreement with direct measurements. Below the transition, CdCr2S4 shows an anomalous heat-capacity contribution and negative thermal expansion, which are in contrast to the conventional behavior found in CdCr2Se4.

► The thermal properties of single-crystalline CdCr2Se4 and CdCr2S4 are studied.
► Pressure dependence of the ferromagnetic transition temperatures is obtained through the thermodynamic relationship.
► CdCr2S4 shows anomalous thermal properties.