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.
参考文献
[1] | Kawaguchi K;Sasaki S;Mukaida H et al.X-Rav diffraction study of a high-Te Bi-Ca-Sr-Cu-O superconductor having imcommensurate superstructure[J].Japanese Journal of Applied Physics,1988,27:L1015-1017. |
[2] | Sequeira A;Rajagopal H;Sastry P V P S S;el al .A neuton diffraction study of the structure of Bi1.6 Pb0.4 Ca1Sr2Cu2Oy[J].Physica C,1991,173:267-273. |
[3] | Hiroshi S;Hideo F;Koukichi T et al.Crystal substructure of the Bi-sr-cu-O System[J].Japanese Journal of Applied Physics,1988,27:L830-832. |
[4] | Goodman P;Miller P;White T J et al.Symmetry detemination and Pb-Site ordering analysis for the n=1,2,PbxBi2-xSr2Can-1 CunO4+2n+δ compounds by convergent-beam andselected-area electron diffracdon[J].Acts Cryst,1992,B48:367-389. |
[5] | 周公度.晶体结构测定[M].北京:科学出版社,1981:253. |
[6] | Takashi O;Tsuyoshi K;Makoto H et al.High-resolution eleectron microscopy and electron diffraction study of allincommensurate Bi1.8Sr1.5Ca1.5Cu2.2Ox superconductor[J].Japanese Journal of Applied Physics,1989,28:L1775-1778. |
[7] | Hiroi Z;lkeda Y;Takano M et al.Modulated structure in Bi2+xSr2-xCu1+yO6+8[J].J Mater P.es,1991,6:435-445. |
[8] | Zhu Y;Tafto J .Direct Imaging of charge moduladon[J].Physical Review Letters,1996,76:443-446. |
[9] | Hran J I;Goldstein J I;Joy D C.Introduction to analytical electron microscopy[M].New York:Plenum Press,1979:387-395. |
[10] | 边为民 .Bi系高温超导体的分析电子显微镜研究[D].东北大学,1997. |
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