Simulation of PAC spectra for spin 5/2 probes diffusing via a simple vacancy mechanism in Cu 3 Au-structured intermetallic compounds

Abstract

Because of its sensitivity to point defects atomically close to probe nuclei, it is reasonable to expect that perturbed angular correlation (PAC) spectroscopy has the potential to assist in the identification of diffusion mechanisms. It is of interest to characterize under what conditions diffusing defects are visible and how the defects affect relaxation in PAC spectra. This was investigated using a stochastic model to simulate PAC spectra for the special case of non-impurity PAC probes diffusing via a simple vacancy mechanism on the Cu-sublattice in Cu 3 Au-structured compounds.

Modeling complex diffusion mechanisms in L1 2 -structured compounds

“…In both models, defect jumps were constrained so that each defect always had at least one near neighbor defect, which is appropriate when there are significant attractive interactions among defects. Spectra were simulated using the Stochastic Hyperf ine Interactions Modeling Library (SHIML) [2], and selected results for the divacancy and the six-jump cycle mechanisms are shown along with results for the simple vacancy mechanism [3] for comparison in Fig. 1.…”