Anisotropic magnetic properties of RCd_1-Sb₂ (R = Ce-Nd) single crystals

We report the magnetic properties of tetragonal compounds RCd1-delta Sb2 (R = Ce-Nd) by means of magnetic susceptibility, heat capacity, and electrical resistivity measurements. A ferromagnetic ordering at TC approximate to 3 K, a nonmagnetic singlet ground state, and an antiferromagnetic ordering at TN approximate to 2.4 K is observed in CeCd1-delta Sb2, PrCd1-delta Sb2, and NdCd1-delta Sb2, respectively. The trivalent nature of the rare-earth atoms has been confirmed from the effective magnetic moment estimated from the paramagnetic susceptibility data. The isothermal magnetization shows that the easy axis of magnetization is along the [100] direction for both CeCd1-delta Sb2 and NdCd1-delta Sb2. From the crystal electric field (CEF) analysis, based on the point charge model, we have analyzed the magnetic susceptibility, magnetization, and the heat capacity data and estimated the CEF split energy levels of CeCd1-delta Sb2 and NdCd1-delta Sb2.