Influence of Dopants and Deformation Temperature on the Strength of GaAs

To analyze the effects of dopants, such as Si, Zn, and Cr, and of the deformation temperature onto the critical resolved shear stress of GaAs, compression experiments are made in the temperature range from 673 to 923 K in argon atmosphere. It is found that the lower yield stress increases approximately in the following order: Cr-doped, undoped, Zn-doped, and Si-doped GaAs in the temperature range from 673 to 773 K; and undoped, Cr-doped, Zn-doped, and Si-doped GaAs in the temperature range from 773 to 923 K. Up to now, it is reported that the addition of acceptortype dopants (e.g. Zn) decreases the yield stress compared with undoped GaAs, but it is found in this experiment that the addition of Zn increases the yield stress. The apparent difference of the dislocation structures between Si-doped and Zn-doped GaAs deformed at 723 K are observed by transmission electron microscope and the Peierls barriers of Si-doped GaAs are considered to be higher than that of Zn-doped GaAs.