Abstract
We investigate the antiferromagnetic insulating nature of Ca3FeRhO6 both experimentally and theoretically. Susceptibility measurements reveal a Neel temperature of T-N similar or equal to 20 K and an effective magnetic moment of 5.3 mu(B)/fu. Mossbauer spectroscopy strongly suggests that the Fe ions, located at trigonal prismatic sites, are in a 3+ high-spin state. Transport measurements display a simple Arrhenius law, with an activation energy of similar to 0.2 eV. The experimental results are interpreted with local spin-density approximation band-structure calculations, which confirm the Fe3+ state, the high-spin versus low-spin scenario, the antiferromagnetic ordering, and the value for the activation energy.