Monovacancies and Na substitutional defects in PbTe: theoretical positron annihilation study

16th International Conference on Positron Annihilation

Liu, J.D.^1,2 ; Cheng, B.^1,2 ; Zhang, L.J.^1,2 ; Zhang, J.^1,2 ; Weng, H.M.^1,2 ; Ye, B.J.^1,2

State Key Laboratory of Particle Detection and Electronics, University of Science and Technology of China, Hefei 230026, China^1

Department of Modern Physics, University of Science and Technology of China, Jinzhai Road, Hefei, Anhui, 230026, China^2

关键词: Electron structures;    Generalized gradient approximations;    Momentum distributions;    Plane wave methods;    Positron lifetime;    Pseudopotentials;    State of the art;    Substitutional defects;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/443/1/012030/pdf
DOI  :  10.1088/1742-6596/443/1/012030

来源: IOP

【 摘 要 】

The electron structures of cubic PbTe and substitutional defects are investigated using the state of the art pseudo-potential plane wave method, in the framework of the density functional theory within the generalized gradient approximation. The structural dependent positron annihilation in cubic PbTe was calculated and the positron lifetimes of the bulk, the Pb mono-vacancy, the Te mono-vacancy and the Na atom substituting on Pb were calculated respectively. The study provides evidence that positrons can distinguish between mono-vacancies and in situ substitutional Na doping. The positron lifetime values were found to be too similar to be distinguished. But calculations of the positron annihilation momentum distribution spectra did show clear differences between the two types of defect and may be exploited to characterize substitutional defects.