Optimization for preparing Bi 1.68 Pb 0.32 Sr 1.75 Ca 1.85 Cu 2.85 O 10+y powders by wet ball milling

Superconducting Bi 1.68 Pb 0.32 Sr 1.75 Ca 1.85 Cu 2.85 O 10+ y (Bi-2223) powders were prepared by a conventional solid-state reaction using hand grinding and wet ball milling. The effects of the ball milling and sintering times on the phase evolution were examined by x-ray diffraction and magnetic susceptibility measurements. Single-phase Bi-2223 powders with a superconducting transition temperature of about 108 K were optimally prepared by wet ball milling for 20 h and sintering at 867 °C for 80 h. Finding these optimal preparation conditions were crucial for mass producing high-quality single-phase Bi-2223 precursor powders with a much lower cost of energy. Furthermore, we found that ball milling led to thinner grains than hand grinding.