Magnetic phase transitions in intermetallic CeCuGe compound

Electrical and magnetic properties of CeCuGe were investigated through electrical resistivity, thermal conductivity and magnetization measurements in the temperature range 2-300 K. Magnetization measurements indicate a paramagnetic to ferromagnetic transition at T=10 K, in agreement with previous work. There are two distinct paramagnetic regimes: At high-T the magnetic moment per cerium is 2.50 μ_B, nearly equal to the expected 2.54 μ_B for Ce³⁺, while at low-T the effective moment decreases to 2.20 μ_B per cerium. This decrease is attributed to crystalline electric field effects. In the ferromagnetic region, the hysteresis curve indicates a rather small anisotropy (H_c less than 20 Oe). There is also very little remanence (the ratio of the remanence to the technical saturation magnetization is about 0.05), implying that this material is magnetically quite soft, with a very small magnetocrystalline anisotropy, contrary to what was reported in a previous investigation. In the temperature regime 10-30 K the resistivity obeys a T²-behavior, consistent with the appearance of spin fluctuations above the ferromagnetic transition. In the same temperature regime, the thermo-power exhibits a linear rise in addition to a T² term, anomalous behavior which we also attribute tentatively to the development of spin fluctuations.