An efficient technique for growing (Bi,Pb)-2223 single crystals

An efficient KCl-flux technique is presented for growing large amounts of (Bi,Pb)₂Sr₂Ca₂Cu₃O _10+δ or (Bi,Pb)-2223 single crystals with high reproducibility. In this technique single-phase (Bi_0.85Pb_0.15) ₂Sr₂Ca₂Cu₃O_10+δ coarse-grain powder is added to act as seeds for growing single crystals in the Bi-Pb-Sr-Ca-Cu-O solute that otherwise contains as little as possible the (Bi,Pb)-2223 and (Bi,Pb)-2212 phases. The (Bi,Pb)-2223 seed powder, the Bi-Pb-Sr-Ca-Cu-O solute powder and KCl were mixed with a weight ratio of (0.01-0.1):1:4, and heated in an alumina crucible in air at 845 °C for 100 h to yield high-quality single crystals with an average size of 80 × 80 × 8 μm³. Using ∼200 single crystals having the c-axis aligned, anisotropic magnetization characteristics were successfully evaluated. Oxygen-annealing effects (both in 1 and 10 atm O₂) on the H _irr characteristics were investigated as well but found rather negligible.