The Structural Characteristics on High Tc Superconducting Oxide

The structural feature on high Tc superconducting oxide is researched according to the results of X-ray of Bi-Sr-Ca-Cu-O system in this paper. The model of two-dimension stacking in which Bi-Sr-Ca-Cu superconducting oxide is considered as multiple stack of Ca-O, Cu-O, Sr-O, Bi-O atomic layers defined A, B, C, D layers respectively is proposed. These atomic layers can be able to stack in variant styles along c-axis and be able to form a number of various phases which have different cell parameters c and own (001) plane in common. Stacking also can form variant transform conditions. Meanwhile, the serious lattice distortion in a, b direction can be emerged due to the varied defects which almost close to continous distribution. The variety of structures, phases and defects can be occured when the order phases of stacking and the disorder phases of stacking overlap each other. The model of two-dimension stacking also interprets why it is difficult to grow large size single crystal under normal conditions without twins and defects, and also hints that the single crystals without twins and defects may have fairly good superconductivity.