摘要
本文根据Bi-Ca-Sr-Cu氧化物超导体的X射线衍射结果,提出高Tc氧化物超导体的二维体系堆积模型,其结构特征是由不同组成A、B、C、D层沿c轴方向进行多种类型的堆积。在某些区域堆积很有规律,形成一定的超点阵有序相,而在另一些区域堆积的规律常常受到破坏,当有序相堆积相互交错时,就会造成结构、物相、缺陷的多样性。
The structural feature on high Tc superconducting oxide is researched according to the re- sults of X-ray of Bi-Sr-Ca-Cu-O system 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 lay- ers 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 direc- tion can be emerged due to the varied defects which almost close to continous distribution. The variety or 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 fair- ly good superconductivity.
