Anisotropic Magnetic Properties of a Pressure-induced Superconductor Ce2Ni3Ge5

Abstract

Single crystals of a pressure-induced superconductor Ce 2 Ni 3 Ge 5 have been successfully grown by the flux method. The anisotropic magnetic properties due to the orthorhombic crystal structure have been studied precisely by the electrical resistivity, specific heat, magnetic susceptibility, and high-field magnetization measurements. The results of these measurements confirmed two antiferromagnetic transitions at T N1 =5.0 K and T N2 =4.3 K. The electronic specific heat coefficient obtained from the low-temperature specific heat data amounts to 90 mJ/K 2 ·mol Ce. The high-field magnetization for H ∥[100] shows four magnetic transitions at 11.8, 12.9, 17.5 and 23.9 T with a saturation moment of 0.73 µ B /Ce at 1.3 K. On the other hand, two magnetic transitions are observed for H ∥[010] and [001], with saturation moments of 0.43 and 1.1 µ B /Ce, respectively. We have also performed the crystalline electric field (CEF) analysis on the magnetic susceptibility and magnetization to understand the magnetocrystalline anisotropy, where the splitting energies of two excited doublets in the CEF scheme are estimated to be 140 and 576 K, respectively.