Muon spin relaxation in synthetic type IIa diamond grown by high-pressure and high-temperature (HPHT) synthesis

The behaviour of hydrogen in the low strain pure diamond material synthesized by the high pressure high temperature (HPHT) route has been studied using the longitudinal field muon spin relaxation technique (LF-μSR)(LF-μSR). This study almost completes a survey of muonium in diamond with a range of defect compositions. The result may provide information on the so-called missing fraction (MF) observed in many previous studies of muons implanted into semiconductors. The experimental results showed the existence of a diamagnetic muon state (μ+)(μ+), two paramagnetic muonium states (tetrahedral interstitial (MuT0) and bond-centred (MuBC0)), and MF formed by positive muons implanted into the sample. The absolute fractions of μ+μ+, MuT0, MuBC0 and MF in the sample were 4%, 54%, 30% and 12%, respectively.