Abstract. We present the miscibility gap for the In_xGa_1−xSb_yAs_1−y quaternary alloys in the regular solution model. The miscibility gap is described in terms of the minimum condition for the free energy of the two-phase decomposed alloy. The alloys are considered in the simple solution and quasichemical approximations. Interactions between the nearest and next nearest atoms as well as the oscillation motion of atoms are taken into account. The miscibility gap of the In_xGa_1−xSb_yAs_1−y alloys is calculated at temperatures of 500, 550, 600 and 650 °C. It is shown that the more correct quasichemical approximation indicates a less extended miscibility gap.

Print publication: Issue 22 (9 June 2004)
Received 24 September 2003
Published 21 May 2004