Electric, magnetic, and thermal properties of Ce2NiGe3:: A Kondo lattice compound showing spin glass behavior -: art. no. 224405

The magnetism of Ce2NiGe3 was investigated by measuring magnetic susceptibility chi, electrical resistivity rho, thermoelectric power S, and specific heat C. dc susceptibility shows irreversible behavior at low temperatures. In a low external magnetic field, the field-cooled susceptibility increases monotonically with decreasing temperature. On the other hand, the zero-field-cooled susceptibility shows a peak at 3.5 K, which was estimated as the freezing temperature T-f. The magnitude of the peak decreases with increasing field. No anomalies were found in resistivity and in specific heat at T-f. Instead, a broad peak of the specific heat was observed at a higher temperature 1.3T(f). The magnetic contribution to the specific heat C-m shows a Schottky peak around 60 K, giving the scheme of crystal field splitting: Delta (1) = 135 K and Delta (2) = 498 K. The specific heat coefficient gamma was estimated to be 25 mJ/K-2 mol Ce from the data below 1 K. Magnetic resistivity shows a - 1n T dependence from room temperature to 50 K. The thermoelectric power shows a broad positive peak around 80 K and a negative peak at 20 K. Ce2NiGe3 was found to be a new Kondo lattice compound showing spin-glass behavior. Frustration and disorder play a crucial role in the formation of the spin-glass state.