摘要
用 X 射线旋进照相、电子衍射和 TEM 方法观察到 Bi 系超导材料中某些类多型结构特征,显示了一维无序结构及衍射的弧化效应、带状结构均与它存在交生现象有关;用类多型结构特征阐明 BiO 层结构中 Bi^(+++)的位移将导致 BiO 层中多余的氧正是其超导电性改变的一种标志。
Some studies of the polytypoidic structure in Bi-system superconductors byX-ray precession photographs,electron diffraction and TEM technique are made.A strongincommensurate modulation reflections were observed by these methods in Bi-system 2223phase.The Laue steaks by the 1D disorder,and the banded structure on the prependicular toc-axis had been revealed.The“arcing effect”on the X-ray precession photographs by theintergrowth in Bi-system superconductors was observed.It is one of the polytypoidism reflec-tions that take place in the Bi-O layers.It is also evident that the polytypoidic concept allow usto describe the structure and its physical properties of these superconducting in a unifiedmanner.However,the polytypoidism is influenced by changes that take place in Bi-O doublelayers.So it is shown that the polytypoidism are generic feature to results presented in Bi-sys-tem superconductors.
基金
国家自然科学基金 5880057
关键词
BI系
超导材料
类多型性
Bi-system high-T_c superconductors
polytypoidism
intergrowth
arcing effect
one dimension disorder
