Theoretical investigation of disorder effect on positron states in GaxIn1-xAsySb1-y/GaSb

A pseudopotential formalism under the virtual crystal approximation with an d without incorporating the effect of the alloy disorder is applied to stud y the positron behaviour in cubic GaxIn1-xAsySb1-y quaternary system lattic e matched to GaSb. To the best of our knowledge, this is the first time a s tudy has been carried out on such an alloy. The positron wavefunctions have been calculated employing the point-core approximation for the ionic poten tial. Our results show that the positronic properties are generally very we akly affected by the alloy disorder. (C) 2001 Elsevier Science Ltd. All rig hts reserved.