Evidence for muonium passivation in n-doped Ge

Two different diamagnetic muon states have been identified through their response to bulk electronic excitation in crystalline n-type Ge: one, found above similar to 100 K, rapidly charge exchanges with photogenerated carriers, while the other, seen at low temperatures, shows Little or no such behavior. The electronic inactivity of the latter state (Mu(-), produced by a slow charge-transfer reaction between muonium and an impurity donor atom) further suggests that the electronic level is located outside the energy-band gap, equivalent to ''muonium passivation'' of the donor.