SYNTHESIS OF HIGH CRITICAL CURRENT YBA2CU4O8 SUBMICRON POWDERS AT ONE ATMOSPHERE PRESSURE BY THE CITRATE-GEL PROCESS

High-Tc superconducting YBa2CuO4O8 submicron powders are successfully synthesised via citrate-gel process at one atmosphere oxygen pressure. The resulting material had a stable and reproductible superconducting transition temperature around 80K. The intra-grain critical current density has been up to 1.3×107 A/cm2 at 6K and H=1T. This technique can be employed in a large-scale preparation of the YBa2Cu4O8 powders