First principles calculation of noble gas atoms properties in 3C–SiC

Abstract

First-principles calculations were performed to investigate the properties of single noble gas atoms (He, Ne, Ar, Kr, Xe) in 3C-SiC. Three cases were considered: (i) a noble gas atom in a perfect crystal, (ii) in the neighborhood of a monovacancy, (iii) and of a divacancy. For each case the stable configurations were determined, as well as their formation energies. The mobility of He, Ne and Ar interstitials was studied, and the associated migration energies were calculated. Our results were discussed and compared to available experimental or theoretical works.

Site preference and diffusion behaviors of H influenced by the implanted-He in 3C-β SiC

“…We then consider the influence of He retention on the site preference of H in SiC. By introducing He into the pure SiC at various sites, we find the favorite site for He in SiC is the Tsi interstitial site, being in consistent with the literatures[21][22][23]. For convenience, we denote the He-implanted SiC as SiC+He.…”

Vacancy effects on the formation of He and Kr cavities in 3C-SiC irradiated and annealed at elevated temperatures

“…After a high-dose Kr ion implantation at 750˚C, a supersaturated concentration of vacancies was produced in the SiC. Upon annealing at 1600˚C, vacancies become mobile leading to The results may validate a first principles calculation [23] that shows that Kr can be trapped at vacancies. From Fig.…”

Atomic scale mobility of the volatile fission products Xe, Kr and I in cubic SiC

“…The results of Wiktor et al [18] indicated that the carbon vacancy is in the 2+ charge state over nearly the full theoretical band gap (1.38 eV), although at the top of the band gap the neutral carbon vacancy was predicted to be favourable. Previously Bertolus et al [19] and Charaf-Eddin and Pizzagalli [20] used DFT to investigate the incorporation of a number of fission products into neutral defects of SiC, including Xe, Kr and I. The substitution of fission products onto the carbon sublattice was widely predicted to be very significantly more favourable than as an interstitial or on the Si sublattice.…”