Continuous processing of Bi2Sr2CaCu2O8+δ precursor powders

Abstract

A continuous solid-state process inside a roller furnace has been used to fabricate Bi-2212 powders. These powders were synthesized for their use as precursors to obtain textured monoliths by laser induced directional solidification. A thermal cycle has been defined, which depends on the length of the furnace, the prefixed temperature profile and the velocity of the sample inside the furnace. Powder properties have been studied as a function of the number of processing cycles. Phase evolution has been analyzed using X-ray diffraction, while other relevant properties of the powders, including grain size distribution, thermal behavior and temperature dependence of the AC susceptibility, have also been measured. These properties have been compared with those of commercial powders and precursors prepared using a standard solid-state protocol. Textured samples using these continuous solid-state precursors exhibit superconducting properties comparable to those similarly processed but prepared from commercial powders.