MUONIUM DYNAMICS IN SI AT HIGH-TEMPERATURES

We report longitudinal muon-spin-relaxation measurements in intrinsic Si from 350 to 850 K. The data are explained by a two-state model describing alternating charge states of muonium resulting from thermally excited electrons. Within this model, the average muon-electron hyperfine parameter in the neutral state is consistent with muonium at the tetrahedral interstitial site. This indicates that at the highest temperatures measured neutral muonium spends significant time away from the bond center site, the calculated adiabatic potential minimum.