Possible Model of the Modulated Structure in High-Tc Superconductor in a Bi-Sr-Ca-Cu-O System Revealed by High-Resolution Electron Microscopy
Abstract
A model for the modulated crystal structure (Matsui et al.: Jpn. J. Appl. Phys. in press) in high-Tc superconductor in a Bi-Sr-Ca-Cu-O system is proposed based on the high-resolution electron microscope images. Ideally, it is body-centered orthorhombic with a{=}0.54, b{=}5a{=}2.7 and c{=}3.08 nm. The Bi2O2 layers do not form complete sheets, but contain occupational and/or positional fluctuation of Bi-sites to form “Bi-concentrated bands” which extend in the a-direction. Contraction of lattice planes along the b-axis is induced in the Bi-concentrated bands, causing compensating expansion in the remaining Bi-deficient ones.
- Publication:
-
Japanese Journal of Applied Physics
- Pub Date:
- March 1988
- DOI:
- 10.1143/JJAP.27.L372
- Bibcode:
- 1988JaJAP..27L.372M
- Keywords:
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- Bismuth Oxides;
- Crystal Structure;
- High Temperature Superconductors;
- Mixed Oxides;
- Calcium Oxides;
- Computerized Simulation;
- Copper Oxides;
- Electron Microscopy;
- Strontium Compounds;
- Solid-State Physics