BOND-CENTERED MUONIUM IN DIAMOND - RESOLVED NUCLEAR HYPERFINE-STRUCTURE

The nuclear hyperfine structure of bond-centered muonium in C-13 enric hed diamond has been resolved using time-differential transverse-field muon spin rotation. The measured nearest-neighbor C-13 hyperfine para meters are compared to theoretical values from a recent ab initio Hart ree-Fock type cluster calculation. The ratios of the measured C-13 hyp erfine parameters and free atom values indicate that 92% of the unpair ed electron spin density resides on the two nearest-neighbor atoms, in marked contrast with the situation for the analogous muonium center i n Si.