Synthesis, magnetic and thermoelectric properties of Rh2MO6 (M = Mo, Te, and W) with rutile-related structure

The Rh₂MO₆ compounds with M = Mo, W and Te were synthesized by solid state reaction. The compounds all crystallize in a rutile-type structure. These compounds would be expected to be diamagnetic insulators if the oxidation states were Rh³⁺ and M⁶⁺. In fact, all show relatively high electronic conductivities with Rh₂TeO₆ showing the highest electronic conductivity of ∼500 S/cm at room temperature. Measurable magnetic moments also indicate valence degeneracy between Rh and the M cation. The measured Seebeck coefficients are relatively low and positive indicating hole-type conduction.