Deformation twinning in Bi-Sb crystals under dynamic indentation

Bi-Sb single crystals (with Sb concentration varied up to 30 at. %) have been subjected to impact loading in the form of dynamic indentation on their (111) cleavage planes. The resulting mechanical twins are the theme of this report. The tensile and compressive stresses developed by the spherical indenter employed have been differentiated with respect to their role in producing the twins. While the twins produced in the crystals with Sb less than or equal to 15 at. % are interpreted as being due to tensile stresses, those in the crystals with Sb > 15 at. % are found to be due to compressive stresses.