摘要
根据Bi系超导体的结构特点提出了BiO层中O原子位移调制的结构模型.通过计算机模拟计算了Bi-2212相A型调制结构的选区电子衍射和会聚束电子衍射花样.计算结果表明,O原子的位移调制对电子衍射花样中调制衍射斑的影响甚大,不容忽视.而会聚束电子衍射对O原子的位移更敏感,利用这一特点,进一步调整BiO层中O原子的位移,使模拟计算的电子衍射花样和会聚束电子衍射花样与实验结果完全一致.
The modulation structure model by O atoms displacement in the BiO layers has been proposed according to the structure characteristics of Bi high - Tc superconductor. The selected area electron diffraction （ SAED ） and the convergent beam electron diffraction （CBED） patterns of the modulation model for the Bi -2212 phase have been simulated. The facts that effects of the displacement modulation of the O atoms for the electron diffraction patterns were very obvious indicated that action of the light atoms couldn＇ t be ignored in the electron diffacfion. The effects for CBED patterns were more sensitive than SAED, therefore, the advantage may be utilized to ascertain the O atom sites in the modulation structure of the Bi high - Tc superconductors. The patterns simulated for the SAED and the CBED were identical with the experimental results.
出处
《材料与冶金学报》
CAS
2009年第2期130-134,150,共6页
Journal of Materials and Metallurgy
基金
美国能源部材料科学局
基础能源办公室资助课题
合同号DE-AC02-76CH00016
关键词
Bi系高温超导体
Bi-2212相
调制结构
电子衍射
会聚束电子衍射
Bi high - Tc superconductor
Bi - 2212 phase
modulation structure
electron diffraction
convergent beam electron diffraction
