ENDOR measurements of spin transfer in (VF6)4-

EPR and ENDOR measurements have been made to investigate the covalent spin transfer for substitutional V 2+ in KMgF 3 . The hyperfine parameters for the F - ligands are A=-20.99+or-0.02 MHz and B=-5.70+or-0.04 MHz. Hence, the unpaired spin densities in fluorine 2p pi , 2p sigma and 2s orbits which arise from covalent transfer to, and overlap with, the V 2+ 3d and 4s orbits are estimated to be f pi =(2.6+or-0.3)%, f' sigma =-(0.3+or-0.2)% and f' s =-(0.1+or-0.01) respectively. The covalency model used in interpreting the hyperfine parameters leads to a g factor consistent with the experimental value of 1.972.