Transmission electron microscopy evidence for phase transformation from Bi2Sr2CuO6 to Bi2Sr2Ca2Cu3O10

Abstract

The growth mechanism of the Bi-2223 phase was studied using multifilamentary Ag/Bi-2223 tapes manufactured by the powder-in-tube method. X-ray powder diffraction was performed to analyze the developments of Bi-2201, Bi-2212, and Bi-2223 phases during sintering periods at high temperatures. Transmission electron microscopy (TEM) was used to investigate the growth mechanism of the 2223 phase. TEM images indicated that 2201 and Ca2CuO3 crystals come together to form platelets of 2223. The structural phase transformation established a structural frame of the 2223 crystal. There were some vacant defects retaining in the established 2223 crystal cells at copper and oxygen sites after the phase transformation, and the Cu/O compound at high temperatures would diffuse into 2223 cells and occupy the corresponding vacancies to complete the 2223 crystal structure. The present work provides an evidence for growing the 2223 phase from the 2201 phase and Ca2CuO3 in the samples studied.

Precursor Size Effects on Kinetics Parameters of Bi-2223 Growth

“…The growth morphology of the 2223 phase with solid state reactions mainly depends on synthesis methods, in addition to the properties of precursors and sintering processing [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. Phase development and kinetics of the 2223 phase relate to the synthesis processing [16][17][18][19][20][21][22][23][24][25], as well. Properties of precursor particles, especially grain size of particles, are important factors to obtain high quality 2223 crystals.…”