Transition dynamics for Mu acceptor states in Si1–xGex alloys

Abstract

Quasiclassical trajectory (and variational transition state theory) study of the rates and temperature-dependent activation energies of the reactions Mu+H2 (completely thermal) and H, D, and Mu+H2 (v=0, j=2) Kinetic isotope effects in the Mu+H2 and Mu+D2 reactions: Accurate quantum calculations for the collinear reactions and variational transition state theory predictions for one and three dimensions Abstract. We use the longitudinal field muon spin relaxation technique to observe charge-state and site-change transitions of muonium in Si 1-x Ge x alloys. In this project, we examine the temperature and magnetic field dependences of the relaxation rates for Si 1-x Ge x samples (x = 0.77, 0.81, and 0.84), in the composition range where the acceptor level lies within the band gap. This study particularly focuses on the relaxation rates for Si 0.19 Ge 0.81 to identify various cyclic charge-state and site-change processes as a function of both temperature and magnetic field. We extract the paramagnetic hyperfine constant and the relevant transition rate parameters for site changes and charge-state transitions involving Mu acceptor states for this sample. At small x, a site change dominates the transition out of the neutral T-site acceptor state, while in higher Ge content alloys hole ionization becomes the dominant transition out of the Mu T 0 .

Thermal spike in muon implantation

“…A consequence is that the reaction from compact muonium to the transition state occurs mainly in one direction whereas in thermodynamical equilibrium forth and back reactions are possible. 26 The rather strong dephasing effect in irreversible reactions may explain the weak diamagnetic fraction in transverse field measurements on Si/Ge alloys at low temperatures. 27,28 Figure 4 shows an example for the calculation of the diamagnetic fraction with Eq.…”