Preparation of Bi-Pb-Sr-Ca-Cu-O Superconducting Fibers by the Sol-Gel Method

Abstract
Bi-Sr-Ca-Cu-O superconducting fibers were prepared by the sol-get method. Gel fibers of 0.01–1 mm diameter were directly drawn from a homogeneous viscous sol which was prepared from an aqueous solution of metal acetates containing acetic acid and tartaric acid. Ceramic fibers with the high-T c phase as the main phase were obtained by heating the gel fibers derived from the sol of molar composition of Bi:Pb:Sr:Ca:Cu=1.85:0.35:1.9:2.0:3.1 to 835°C at a slow rate of 0.33°C/min and keeping them there for 40 h. The fiber showed diamagnetism below 110 K and zero electrical resistance at 98 K.