Growth and characterization of (Bi, Pb)₂Sr₂Ca₂Cu₃O_xsingle crystals

(Bi, Pb)₂Sr₂Ca₂Cu₃O_x (2223) single crystals have been grown using a fused-salt reaction of Bi₂O₃, PbO, SrCl₂, CaCl₂, CuCl, and KNO₃ in a KCl flux. The pristine crystals show regular plate-like morphology with typical dimension of 0.1 × 0.1 × 0.001–0.01 mm³. Crystal orientation, chemical composition, phase purity, and superconductivity of the pristine crystals were determined by SEM, TEM, EDX, x-ray diffraction techniques, and SQUID magnetometry. The relative fraction of the Bi-2223 phase (T_c = 110 K) in as-grown crystals is ~97%. The only impurity phase, Bi-2212, occurs in some selected crystals but is present in amounts less than the detection limit of x-ray diffraction and is unobserved in the diamagnetic signal determined by SQUID magnetometry.