EPR of rhodium, osmium and iridium-doped rutile

EPR of Rh2+ (4d7), Rh4+ (4d5), Os3+ (5d5), Os5+ (5d3) and Ir4+ (5d5) have been observed in doped-rutile crystals grown by vapor transport. All the nd5 ions are in their high-field, low-spin, states with orbital angular momentum-reduction factors between 0.85 and 0.36. The Os5+ (5d3) ground state is characterized by a large axial field splitting. Ir4+ is very stable in TiO2 and its optical absorption spectrum is reported. © 1986.