THE TWENTY-ONE ELASTIC CONSTANTS OF TRICLINIC COPPER SULPHATE PENTAHYDRATE

Abstract

The twenty-one elastic constants of TriClinic copper sulphate pentahydrate have been determined at room temperature by the ultrasonic pulse echo method. An iteration technique is used for solving the full cubic Christoffel equation exactly, (J. Indian Inst. Sci., 50 (1968) 170) to obtain the elastic constants of crystals from ultrasonic velocities along arbitrary directions. The  stiffness coefficient, are obtained from measurements along eleven directions. The elastic constants referred to the I.R.E. system of axes are:
c11-5.65; c12-2.65; c13-3.21; c14-033; c15-0.08; c22-4.33; c23-3.47; C24-0.07; c25-0.21; C26-0.20: c34-0.44; c35-0.21; c36-0.16; C44 =1.73; c45=0.09; c46-1.22; c50= -0.26 and c66= 1.00 in units of 1010 N/m2. C55= -0.39; c56=5.69; The results are discussed in relation to other studies on CuSO4, 5H2O.