Magnetic Susceptibility of the Cluster Compounds Mo6Se8 and Mo6Te8

The magnetic susceptibility of the cluster compounds Mo6Se8 and Mo6Te8 has been measured at temperatures between 82 and 330 K, using a Faraday balance. The paramagnetic and diamagnetic components of the susceptibility have been analyzed. The Pauli component was evaluated using the density of states at the Fermi level obtained by band structure calculations, while the core component was evaluated using the calculated atomic core diamagnetism. The paramagnetic susceptibility of Mo6Se8 is due mainly to the Pauli contribution, while the Van Vleck contribution is small, in agreement with the metallic feature of the compound. The paramagnetic susceptibility of Mo6Te8 is due mainly to the Van Vleck term, while the Pauli contribution of the conduction electrons is very small. The result points out that the Mo6 clusters in the telluride retain their molecular character, with small intercluster interactions.