The ionization with temperature of weakly bound muonium atoms in undoped Cd
S has been studied using the technique of muon spin relaxation in a transve
rse magnetic field of 10 mT. For this atom the Coulomb binding energy betwe
en the muon and the electron is sufficiently small that the Landau diamagne
tic term determines the magnetic behavior of the system: due to the diamagn
etic interaction the muon precession in a transverse magnetic field exhibit
s a frequency shift of approximately 0.5% around the ionization temperature
. (C) 2001 Elsevier Science B.V. All rights reserved.