STUDIES ON THE PLASTIC-DEFORMATION OF TL3ASSE3 SINGLE-CRYSTALS BY HARDNESS INDENTATION

The deformation behavior of Tl3AsSe3 (TAS) single crystals has been studied by hardness tests in four different crystal surfaces, the (101¯0), (1¯10), (0001), and the plane where the normal is tilted 19° off the hexagonal c axis in the b-c plane. The dominant slip planes are of the (101¯1) type; the possibility of (101¯0) and (0001) slip was also observed. The observed dependence of force on the length of diamond pyramid indentations implies that TAS behaves to some degree like a ductile metal. Measurements of hardness anisotropy are very useful for defining crystal growth and handling conditions that minimize the effect of stresses.