Heat treatment on phase evolution of Bi-2223 precursor powder prepared by spray pyrolysis method

Cui Li-Jun^{1, 2}, Zhang Ping-Xiang^{1, 2, 3, †}, Li Jin-Shan¹, Yan Guo², Feng Yong², Liu Xiang-Hong², Li Jian-Feng², Pan Xi-Feng², Yang Fan², Zhang Sheng-Nan³, Ma Xiao-Bo³, Liu Guo-Qing³

(a) Curves of heat flow versus temperature for precursor powders at heating rate of 2 °C/min in following air (red) and N₂-0.1%O₂ (black); (b) x-ray diffraction patterns of precursor powders after heat treatment at 770 °C/6 h in air (red) and N₂-0.1%O₂ atmosphere (black) (2212:Bi-2212, 2201:Bi-2201), CP:Ca₂PbO₄, AEC: (Sr,Ca)_xCu_yO_δ.