Radiation enhanced dislocation glide effect on indentation-induced fracture of GaAs single crystals

The laser illumination effect on the growth of cracks formed by Vickers indentation on (111)Ga and (111)As faces of n-GaAs is studied from room temperature to 400°C. It was found that whether the effect is gained depends on both the polarity of the indented surface and the crack direction: cracking on (111)Ga faces was suppressed by light illumination, which, however, had no effect on cracking on (111)As faces. These results were explained in terms of the mobility difference between α(As(g)) and β(Ga(g)) dislocations and of the radiation-enhanced glide effect on these dislocations.