Magnetic Phase Diagram And Crystalline Electric Field Of Ndru2al10 Single Crystal

We measured specific heat of NdRu2Al10 single crystal under magnetic field along a-axis in order to investigate basic physical properties of this compound. We found three anomalies at T-1 similar to 2.4 K, T-2 similar to 1.2 K and T-3 similar to 0.9 K in the temperature dependence of specific heat. These anomalies are attributed to antiferromagnetic order. In addition, we observed a Schottky-type anomaly, which reflects splitting of crystalline electric field (CEF). The entropy reaches Rln2 just above T-1 and almost reaches Rln10 at room temperature. These results indicate that these three phase transitions occur in a doublet ground state and that all CEF levels of J = 9/2 are below 300K. The results of specific heat are consistent with the CEF level scheme proposed by magnetization measurement.