Electronic band structure calculations on the antiferromagnetic ternary compounds Ce3Ni2X7 (X = Ge and Sn) and CeNiGe3

The electronic structure of the cerium intermetallic systems Ce3Ni2X7 (X = Ge and Sn) and CeNiGe3, which are structurally related and antiferromagnetically ordered, are examined both experimentally using X-ray absorption spectroscopy at the Ce L-III-edge as well as theoretically by local spin density functional theory using the augmented spherical wave (ASW) method. The influence of hybridisation of the 4f(Ce) states on the chemical bonding and magnetic behaviour of these ternary compounds is discussed with reference to the densities of states (DOS) projected on to the atomic sites. From this we propose a mechanism to explain the respective behaviours of the cerium atoms at the different crystallographic sites. The magnetic properties are discussed from a spin-only viewpoint; spin-orbit coupling effects are inferred from previous calculations.