Elasticity studies of aluminium-substituted highT c superconducting materials

Longitudinal and shear wave velocities of Al-substituted Bi-Sr-Ca-Cu-O superconducting materials prepared by the ceramic technique were measured by the pulse transmission technique. Using the data, several elasticity parameters like Young’s modulus, rigidity modulus, Poisson’s ratio, Debye temperature etc were evaluated. Variation of elasticity parameters with composition has been explained in terms of binding forces between various atoms of the superconducting materials. Temperature variation of longitudinal wave velocity has also been measured and attempts have been made to explain the anomalies at 200 K.