Elastic properties of gallium substituted Bi (Pb)-2212 superconducting system at 300Â K

The elastic behaviour of Bi1.7−xGaxPb0.3Sr2Ca1Cu2Oy (x = 0.0-0.3) superconducting system has been studied using ultrasonic pulse transmission technique at 1 MHz (300 K). The values of Young's modulus, rigidity modulus, longitudinal modulus, bulk modulus, Poisson's ratio and Debye temperature of the specimens are computed from longitudinal and shear wave velocities and corrected to zero porosity. The strength of interatomic bonding is found to increase on gallium substitution, in consistency with Al-substituted Bi (Pb)-2223 system. The applicability of the heterogeneous metal mixture rule for estimating elastic constants and critical temperature has been tested, and agreement with the experimental results validates the method used.