PLASTIC-DEFORMATION OF GAAS BY ULTRASONIC TREATMENT

For the first time we have obtained plastic deformation of A(III)B(V) semiconductors by ultrasonic treatment at high amplitudes. For tempera tures above 520 K the plastic deformation of predeformed GaAs:Zn by ul trasonics has been detected by observing the multiplication and rearra ngement of dislocations and also a sudden change of internal friction. From the sinusoidal distribution of vibration stress amplitude inside the sample it is possible to determine the stress at which the reorie ntation of predeformation-induced dislocatiins starts, as well as the stress at the beginning dislocation multiplication. Transmission elect ron microscopy investigations show a good agreement of the value of th e stress where the multiplication by ultrasonic treatment begins with the yield stress obtained by uniaxial compression. However, the rearra ngement of dislocations begins at lower stresses than that needed to r each multiplication.