Structure of the High Tc Superconductor, Ba2LaCu3-xO7-y –Studies on La-Ba Ordering and Oxygen Defects
- 1 July 1987
- journal article
- Published by IOP Publishing in Japanese Journal of Applied Physics
- Vol. 26 (7A) , L1244
- https://doi.org/10.1143/jjap.26.l1244
Abstract
Crystal structures of semiconductor Ba2LaCu3-x O7-y sample and 56.5 K superconductor sample, which was obtained by annealing the former in O2, were determined by X-ray Rietveld analysis. The ordering of Ba and La has been clarified by the use of the anomalous dispersion effects. An increase in the site occupancy factor of square planer oxygen (O(2):at z=0) around Cu(1) and shortening of Ba-O(2) distance were observed in the high T c sample compared with the semiconductor. This oxygen behavior, i.e. formation of fully occupied square planer oxygen group (O(1)×2+O(2)×2) around Cu(1), determines the appearance of the superconductivity.Keywords
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