First-principles calculations for intrinsic defects in MgO: Positron lifetime and momentum distribution of electron–positron pairs

Abstract

We presented first-principles calculations of the formation energies for various charge states of intrinsic defects in magnesium oxide, including VO, VMg, VMg+O, VO+Mg+O, and VMg+O+Mg. These results can be used to predict their thermodynamic stability and detectability of these defects via positron annihilation spectroscopy. We employed two-component density functional theory to compute the positron annihilation properties, incorporating the effects of temperature and spin polarization. We then performed calculations of the momentum distributions of annihilating electron–positron pairs in these intrinsic defects in MgO. Using one-dimensional momentum distributions (Doppler-broadening spectra), we calculated the line-shape parameters Srel and Wrel. Our positron lifetime calculations were compared with experimental data. These research provides insight into the positron annihilation characteristics of defects in MgO.