Bi2-xPbxSr2Ca2Cu3Oy superconductors with the nominal substitution parameter
x = 0.0, 0.18, 0.22, 0.25, 0.3, 0.35 and 0.5 were prepared by the usual so
lid-state reaction. The superconducting and mechanical properties of these
compounds have been investigated by measuring electrical resistivity, X-ray
diffraction, surface morphology and microhardness. These measurements reve
aled that the superconducting transition temperature T-c(0) formation of hi
gh T-c-phase, Young's modulus, yield strength and microhardness increased g
radually with a rise in Pb concentration. The maximum of all these paramete
rs occurs for the compound with x = 0.3. This behaviour may be attributed t
o the fact that the intergranular links strengthen and these regions are ma
de more homogeneous up to x = 0.3 and later there is a reduction. This redu
ction may be ascribed to weakening of the intergranular links. These result
s are explained on the basis of low and high-T-c phases and bulk hardness.
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