ANOMALOUS FREQUENCY SHIFT OF NEGATIVE MUON SPIN PRECESSION IN N-TYPE SILICON

The dependence of the residual polarization of negative muons in n‐type Si with impurity concentration (1.6\pm 0.2)\times 1013\ cm-3 on temperature in the 10–300 K range has been investigated. Measurements were carried out in external magnetic field of 0.08 T transverse to the muon spin. Muon spin relaxation and frequency shift were observed at temperatures below 30 K. The relaxation rate at 30 K is equal to 0.25\pm 0.08\,μ s-1. The frequency shift at 20 K is equal to 7\times 10-3. Both the relaxation rate and the frequency shift grow with decrease of temperature. Below 30 K the relaxation rate is well described by the dependence \varLambda=bT-q, where q=2.8.