Shallow acceptor centres in silicon studied by means of spin rotation of negative muons

The residual polarization of negative muons has been studied for phosphorus -doped ([P]: 1.6 x 10(13) cm(-3)) and antimony-doped ([Sb]: 2 x 10(18) cm(- 3)) silicon crystals. The measurements were carried out in a transverse mag netic field of 0.1 T over the temperature region 4 K-300 K. The ionized and neutral states of the Al-mu pseudo-acceptor were observed in antimony-dope d silicon for the first time. The rate of transition from the neutral to th e ionized state of the acceptor was found to be equal to 1.2 x 10(6) s(-1) over the temperature range 4 K-12 K. The estimated rates of relaxation of t he magnetic moment of the acceptor-centre electron shell are 5 x 10(10) s(- 1) and 1.6 x 10(12) s(-1) in phosphorus-doped silicon and 6 x 10(11) s(-1) and 6.7 x 10(12) s(-1) in antimony-doped silicon at 4 K and 15 K respective ly. The experimental results obtained are interpreted in terms of spin-latt ice relaxation of the acceptor magnetic moment and of the acceptor-donor pa ir formation.