Novel behavior of bond-centered muonium in heavily doped n-type silicon: Curie-like spin susceptibility and charge screening

Bond-centered muonium (Mu(BC)(0)) has been observed in very heavily doped n -type Si:P. It exhibits a Curie-like electronic spin susceptibility which l eads to a giant negative shift in the muon spin precession frequency.;At hi gh dopant levels, the Mu(BC)(0) hyperfine parameters, deduced from a model involving spin exchange with free carriers, are significantly reduced from those in intrinsic Si. This indicates that the spin density distribution fo r Mu(BC)(0) in metallic SI:P is altered significantly by charge screening e ffects, likely a general phenomenon for deep impurities in materials with h igh carrier concentrations.