Muon spin rotation experiments on a silicon crystal doped with¹³C

Abstract

A crystal of silicon doped with carbon enriched to 60.1% in¹³C was studied byμSR to determine whether¹³C hyperfine structure could be observed in the frequency spectra of normal muonium, Mu, or anomalous muonium, Mu^*. Measurements at 100 G and 100 K with 40 million good events yielded extremely weak Mu^* signals and no Mu in these data or in measurements at 10 G and 150 K. Transmission electron micrographs of this sample contained small regions showing strain contrast and structure factor contrast. Annealing the sample at 900°C for 84 hours led to featureless electromicrographs. SubsequentμSR measurements yielded a strong Mu^* signal but still no Mu. No broadening due to¹³C was observed.