Positron Annihilation Studies in SixSn1?x and GexSn1?x Alloys

Abstract

The angular correlation of positron annihilation radiation (ACPAR) along different crystallographic directions in Si x Sn 1-x and Ge x Sn 1-x is calculated. We observe that the electron-positron momentum density increases rapidly with increasing Si and Ge content. The computational technique used here is based on the independent-particle model (IPM) coupled with the use of the electron pseudowave and the virtual crystal approximation (VCA) which incorporates compositional disorder as an effective potential. We also present the variation of the positron lifetime in these alloys.