Dependence of some Bi1.7Pb0.3Sr2Ca2Cu3Oy physical properties on the annealing period

By using solid state ceramic synthesis technique, we have produced high-T-c superconducting ceramics with a fixed nominal composition of Bi1.7Pb0.3Sr2 Ca2Cu3Oy (BSCCO). Annealing treatments in air at 800 degreesC for different time periods from 6 to 30 h were carried out for the BSCCO samples. The in fluence of annealing time on the superconducting and mechanical properties were examined by measurements of thermoelectric power (TEP), X-ray diffract ion, surface morphology, bulk density and Vickers microhardness (VHN). The results reveal that the most appropriate annealing time to obtain the highe st peak intensity of high-T-c phase (2223), highest and sharpest transition temperature (T-c(0)), maximum value of density and maximum of VHN is 18 h. Prolongation of the annealing time was associated with a reduction of all these parameters. These observations show that the annealing treatment play s an important role for producing consolidate superconducting compounds wit h improved mechanical properties.