OPTIMIZATION OF INTERACTION PARAMETERS FOR GAXIN1-XASYP1-Y SOLID-SOLUTIONS USING GAS-SOLID EQUILIBRIUM DATA AND A SUBLATTICE MODEL

The interaction parameters for the GaxIn1-xAsyP1-y solid solutions in equilibrium with the source gases used for growing them by VPE (vapour phase epitaxy) have been optimised; This has been achieved by combini ng a sublattice model with our own and other experimental gas and soli d phase compositions. When these optimised values are used a good agre ement between the experimental and calculated solid phase compositions is observed. The usefulness of these parameters in carrying out sever al thermodynamic analyses is exemplified by the deduction of activity of each of the species and a model gas composition-solid composition c orrelation using the generalised computerised equilibrium calculation method, THERMO-CALC.