Magnetic behaviour of the interstitial alloys of the type, CeM_XGe₂ (M=Fe, Co, Ni and Cu)

Abstract

The results of electrical resistivity measurements in the temperature internal 1.4-300 K on the alloys, CeM_XGe₂ (M=Fe, Co, Ni and Cu; 0 < x < 1), crystallizing in the CeNiSi₂-type structure, are reported. Magnetization measurements were also performed on selected compositions for each M. While Fe-containing specimens seem to be non-magnetic Kondo lattices, Ni- and Co-containing specimens exhibit antiferromagnetic Kondo-lattice bahaviour, with T_N⋍3.9 K and 3.0 K respectively. Interestingly, Cu containing specimens order antiferromagnetically at a high temperature (≈17 K), though the paramagnetic Curie-temperature appears to be positive; such a behaviour is uncommon among Ce systems. In addition, a Cu containing alloy, investigated for its magnetization behaviour, shows strong metamagnetic behaviour as a function of externally applied magnetic field.