Effect of Cd Addition on Superconducting Fluctuations and Mechanical Properties of Bi1.82Pb0.36Sr2Ca2CdxCu3Oy System

A study was made of the effect of Cd additions on the superconducting and mechanical properties of Bi 1.82 Pb 0.36 Sr 2 Ca 2 Cd x Cu 3 O y (x=0.0, 0.15, 0.25, 0.35 and 0.55). Characterization of the Cd-samples using XRD, DTA, and SEM techniques, has confirmed that remarkably formation of low-T c phase (2212) by the addition of Cd up to 0.35. High-resolution electrical resistivity p(T) data on the composition of Cd=0.35 have been taken for investigating critically the superconducting fluctuations. Using the Aslamazov and Larkin (AL) and Lawrence and Doniach (LD) models of excess conductivity. Excess conductivity analysis shows that this composition (Cd=0.35) is 2D in the temperature range 137.8-163.7K and a 3D one below 137.8K. Thus, a crossover from 2D to 3D is observed at 137.8K. Sample micro hardness and density are greatly improved by Cd-additions (0.35). This trend is probably due to the intercalation of cadmium between superconducting grains in compositions may provide a plastic-flow region that allows relaxation of undesirable stresses resulting from the grain anisotropy of superconductors.