Critical Current Densities in Superconducting Y–Ba–Cu–O Prepared by Chelating Method

Abstract

The critical current of superconducting Y–Ba–Cu–O (YBCO) compounds prepared by the chelating method was investigated. The chelating agents used for this study were iminodiacetic acid (IDA), nitrilotriacetic acid (NTA), hydroxyethylethylenediaminetriacetic acid (HEDTA), ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA) and triethylenetetraminehexaacetic acid (TTHA). The precursor YBCO obtained from metal complexes heving large stability constants, such as HEDTA, EDTA, DTPA, and TTHA, had very fine and homogeneous particles. The critical current density of YBCO in a block of 1×4×15 mm3 which was sintered at 880∼910°C for 24 h, and then anealed at 500°C in O2 flow was estimated to be 500 A/cm2 at 77 K in zero applied magnetic field.