Dependence of some Bi_1.7Pb_0.3Sr₂Ca₂Cu₃O_y physical properties on the annealing period

Physics Department, Faculty of Science, South Valley University, Sohag, Egypt

Corresponding author: Khalil_20002000@yahoo.com

Received: 8 April 2000
Revised: 6 February 2001
Accepted: 6 February 2001
Published online: 15 May 2001

Abstract

By using solid state ceramic synthesis technique, we have produced high-T_c superconducting ceramics with a fixed nominal composition of Bi_1.7Pb_0.3Sr₂Ca₂Cu₃O_y (BSCCO). Annealing treatments in air at 800 °C for different time periods from 6 to 30 h were carried out for the BSCCO samples. The influence of annealing time on the superconducting and mechanical properties were examined by measurements of thermoelectric power (TEP), X-ray diffraction, surface morphology, bulk density and Vickers microhardness (V H N). The results reveal that the most appropriate annealing time to obtain the highest peak intensity of high-T_c phase (2223), highest and sharpest transition temperature (), maximum value of density and maximum of V H N is 18 h. Prolongation of the annealing time was associated with a reduction of all these parameters. These observations show that the annealing treatment plays an important role for producing consolidate superconducting compounds with improved mechanical properties.