Theoretical Studies of Positron Annihilation in GaP1?xNx

Abstract

Angular correlation of positron annihilation radiation (ACPAR) along different crystallographic directions in GaP1—xNx is calculated. It is observed that the electron–positron momentum density increases rapidly with increasing nitrogen content. The computational technique used here is based on the independent-particle model (IPM) coupled with the use of the electron pseudo-wave function and the virtual crystal approximation (VCA) which incorporates compositional disorder as an effective potential. The variation of the positron lifetime in these alloys is also presented.