Heat treatment on phase evolution of Bi-2223 precursor powder prepared by spray pyrolysis method |
(a) X-ray diffraction patterns of precursor powders heat-treated at 770 °C for 4 h, 8 h, 12 h, 16 h, 20 h, and 24 h in N2-0.1%O2 atmosphere; (b) FWHM value of (Bi, Pb)-2212 phase (0012) as a function of heat treatment time. |