Theoretical investigation of disorder effect on positron states in GaxIn1__xAsySb1 __y/GaSb

A pseudopotential formalism under the virtual crystal approximation with and without incorporating the effect of the alloy disorder is applied to study the positron behaviour in cubic GaxIn1__xAsySb1__y quaternary system lattice matched to GaSb. To the best of our knowledge, this is the first time a study has been carried out on such an alloy. The positron wavefunctions have been calculated employing the point-core approximation for the ionic potential. Our results show that the positronic properties are generally very weakly affected by the alloy disorder.