Synthesis of YBa2Cu3O7−x by chemical precursors

Abstract

An alternative synthetic route for obtaining bulk forms of the high temperature superconductor YBa2Cu3O7−x has been investigated. The approach is based on first preparing the phases Y2Cu2O5 and BaCuO2, followed by a single sintering of an appropriate mixture of these intermediate compounds to produce the superconducting phase. The resulting materials are largely single-phase as shown by x-ray diffraction, and have densities as high as 86% of the theoretical value, and superconducting onset temperatures of 93 K with magnetic shielding factors ranging from 0.85 to 1.02 (±0.05). Metallography and scanning electron microscopy data were also obtained on the best (high Tc, high shielding factors) of the samples. This synthesis approach is believed to be simpler, more reproducible, and has the potential of producing better materials than previously used bulk synthesis methods.