Systematics in the magnetic properties of ternary actinoid oxides

Magnetic data for ternary actinoid oxides with central ions exhibiting the [Rn]5fn electronic structure have been investigated to establish systematics for magnetic behavior and/or relations between structure and magnetism. All compounds with [Rn]5fo central ions exhibit a temperature-independent susceptibility which is ascribed to ligand orbital admixture into the 5f orbitals. The magnetic moments of [Rn]5f1 compounds are composed of a constant and a temperature dependent part, which are ascribed to ligand orbital admixtures and the 5f electrons, respectively. The low temperature behavior of [Rn]5f2n+1 compounds can be qualitatively explained by the lattice structures involved: An-O-An chains are necessary to make superexchange possible and a certain maximum distance between the paramagnetic ions must not be exceeded