Investigations of the oxidation states and spin distributions in Ca3Co2O6 and Ca3CoRhO6 by spin-polarized electronic band structure calculations

Spin-polarized electronic band structure calculations were carried out for the magnetic solids Ca3CoMO6 (M=Co, Rh), and the local electronic structures of their transition metal atoms at the octahedral and trigonal prism sites were examined. Our calculations show that Ca3CoMO6 (M=Co, Rh) has four unpaired spins per formula unit, the magnetic moment comes predominantly from the trigonal prism site, and the metal atoms of both the octahedral and trigonal prism sites have the oxidation state +3.