PREPARATION OF Y2BA4CU7O15-DELTA SUPERCONDUCTOR WITHOUT HIGH OXYGEN-PRESSURE

The synthesis of bulk Y2Ba4Cu7O15-delta superconductor at atmospheric oxygen pressure via solid state sintering is reported. Temperature ran ging from 860 to 890 degrees C as well as time interval over 2 to 15 d ays were used to investigate the formation of the Y2Ba4Cu7O15-delta ph ase. A time-temperature profile characterizing the conditions for the preparation of Y2Ba4Cu7O15-delta phase suggests the optimal condition to be sintering at 890 degrees C for over 10 days. Detailed results of X-ray diffraction, electrical resistivity, iodometric titration and m agnetization measurements are described.