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Imaging Oxygen Vacancies in Superconducting YBa 2 Cu 3 O 7–δ by High Resolution Electron Microscopy
Author(s) -
Tang Dong,
Zhou Wuzong,
Thomas John M.
Publication year - 1987
Publication title -
angewandte chemie international edition in english
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 0570-0833
DOI - 10.1002/anie.198710481
Subject(s) - superconductivity , electron microscope , oxygen , high temperature superconductivity , materials science , condensed matter physics , electron , resolution (logic) , microscopy , crystallography , chemistry , optics , physics , nuclear physics , organic chemistry , artificial intelligence , computer science
In the new high‐temperature superconductors YBa 2 Cu 3 O 7–δ , which have a Perowskite like structure, the oxygen vacancies appear to be of special importance. It is generally difficult to image these vacancies by high‐resolution electron microscopy. However, this has now been definitively achieved by extensive calculations using the “multislice” technique. Under certain conditions of formation—sample thicknesses of 60–80 Å, defocusing adjustment between + 600 and −1800 Å, and a resolution of ca. 2.0 Å—the arrangement of the oxygen vacancies could be determined experimentally. All findings support a recently presented structural model of such superconductors.