Mechanical Properties of Ga_(1–x)In_xAs

Substantial solid solution strengthening of GaAs by In acting as InAs_4 units has recently been predicted. This strengthening could account for the reduction of dislocation density in GaAs single crystals grown from the melt. High temperature hardness measurements up to 700ºC have been carried out on (100) GaAs and Ga_(0.9975)In_(0.0025)As wafers. Results show a significant strengthening effect in In-doped GaAs even at concentration levels of about 0.2 wt%. A temperature independent flow stress region is observed for both these alloys. The In-doped GaAs shows a higher plateau stress level compared to the undoped GaAs. The results are consistent with the solid solution strengthening model.