Weak Kondo Coupling Antiferromagnet CePd3Sn2 with Quasi-One-Dimensional Ce Chains

Abstract

CePd₃Sn₂ with Ce-chains along the orthorhombic b axis has been reported to order antiferromagnetically at T_N ∼ 0.6 K. Above T_N, the specific heat C(T) exhibits a long tail whose origin remains elusive. Here we report on the physical properties of single-crystalline samples inferred from electrical resistivity ρ(T), magnetization M(B), and C(T). The measurements reveal rather weak anisotropic properties characterized by the lowest ρ(T) and the highest saturation M(B) along the b axis. The ρ(T) data along the three principal directions exhibit no clear signature of Kondo scattering and decrease with negative curvatures on cooling from 2 K to T_N = 0.67 K. The magnetic susceptibility and inelastic neutron scattering data are reproduced by the crystal electric field (CEF) model for the Ce³⁺ ion with two excited CEF doublets at rather low energies 27 and 191 K, respectively, above the ground state doublet. The isothermal M(B) curves at 0.3 K show metamagnetic transitions at B || b = 1.8 T and B || c = 1.5 T and upward increases before saturation for the three directions. The antiferromagnetic order is destroyed by the application of magnetic field in an anisotropic way at around B || b = 3 T, B || c = 4 T, and B || a = 5 T. The obtained results are discussed by comparing with those reported for quasi-one-dimensional Ce compounds.