Low-temperature diamagnetic muonium states in n-type gallium arsenide

Zero-field depolarization rates and transverse-field mu SR precession signa ls are investigated for six n-type GaAs samples to obtain information on th e low-temperature diamagnetic muonium state. The onset temperature for grow th of the Mu(T)(-) component shifts downward with n-type concentration, as expected for e(-) capture. A zero-field feature depends on donor species an d concentration, suggesting donor involvement in the low-temperature state, thus supporting assignment to a Mu-donor pair. (C) 2000 Elsevier Science B .V. All rights reserved.