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Calculation of positron lifetimes and momentum distributions of electron-positron annihilation radiation in Mg-doped 3C-SiC
Ist Teil von
Physics letters. A, 2024-03, Vol.501, Article 129374
Ort / Verlag
Elsevier B.V
Erscheinungsjahr
2024
Link zum Volltext
Quelle
Elsevier ScienceDirect Journals Complete
Beschreibungen/Notizen
We calculated the formation energies of various charge states for MgC, MgSi, MgSi+VC, and MgC+VSi defects in 3C-SiC to assess their thermodynamic stability. Using the two-component density functional theory, we determined the positron annihilation lifetimes at 0 K, temperature-dependent positron annihilation lifetimes while considering the electron-phonon coupling interactions, and the positron densities in various charge states of these defects in 3C-SiC. Additionally, the electron-positron momentum distributions were analyzed. Our calculated results largely agree with previous calculations and experimental data, providing a database for the identification of impurity-vacancy complexes in 3C-SiC.
•Contrasting with the Finite Difference (FD) method combined with perturbation theory and the FD method integrated with the Conjugate Gradient (CG) algorithm, our research reveals the unsuitability of the FD method combined with perturbation theory for vacancy cluster calculations.•Our study involved the consideration of electron-phonon coupling interactions to calculate temperature-dependent positron annihilation lifetimes.•Our findings from momentum distribution calculations demonstrate the effective discrimination of Mg-vacancy complexes from intrinsic vacancy defects in 3C-SiC through positron Doppler spectra.