Muonium analog of hydrogen passivation: observation of the Mu+-Zn- reaction in GaAs

Density functional studies of muonium in nitrogen aggregate containing diamond: the Mu(X) centre

Diamond has potential as a wide band-gap semiconductor with high intrinsic carrier mobility, thermal conductivity and hardness. Hydrogen is involved in electrically active defects in chemical vapour deposited diamond, and muonium, via muon spin spectroscopy, can provide useful characterization for the configurations adopted by H atoms in a crystalline material. We present the results of a computational investigation into the structure of the Mu(X) centre proposed to be associated with nitrogen aggregates. We find that the propensity of hydrogen or muonium to chemically react with the lattice makes the correlation of Mu(X) with nitrogen aggregates problematic, and suggest alternative structures.

Dynamics and reactivity of positively charged muonium in heavily doped Si:B and comparisons with hydrogen

The detailed dynamics of the positively charged muonium (Mu+) in heavily doped p-type Si:B is reported. Below 200 K, Mu+ is static and isolated, and is located in a stretched Si-Si bond. Above approximately 200 K, Mu+ diffuses incoherently. At temperatures higher than 300 K, the Mu+-B- complex is formed while above 520 K, it starts to dissociate. There is significant enhancement of the diffusion of Mu+ in Si compared to H+ and D+-this is attributed to its smaller mass.

Local structure of isolated positively charged muonium as an analog for the hydrogen ion in p-type GaAs

We determine the local structure of isolated positively charged muonium (Mu+) in heavily doped p-type GaAs based on muon level crossing resonance and zero applied field muon spin depolarization data. These measurements provide the first direct experimental confirmation that Mu+, and by analogy H+, is located within a stretched Ga-As bond. The distances between Mu+ and the nearest neighbor Ga and As atoms are estimated to be 1.83 +/- 0.10 A; and 1.76 +/- 0.10 A, respectively. These results are compared to existing theoretical calculations on the structure of hydrogen in GaAs and additionally provide data on the induced electric field gradients.