Measurements were made of the dynamics of negatively charged muonium in heavily Si-doped material at temperatures ranging from 295 to 1000K. The muonium began to diffuse, at temperatures above 500K, at a hopping rate which was described by an attempt frequency of 5.6 x 1012/s and an activation energy of 0.73eV. At temperatures above 700K, relaxation from charge-state fluctuations was observed. The data implied that Mu- to Mu0 conversion occurred, via the alternating capture of holes and electrons. This established that Mu was a deep recombination center. Similar dynamics were expected for the isolated H- center in n-type material.

K.H.Chow, B.Hitti, R.F.Kiefl, S.R.Dunsiger, R.L.Lichti, T.L.Estle: Physical Review Letters, 1996, 76[20], 3790-3