Crystallographic study of tetragonal,superconducting YBa2(Cu0.93Fe0.05)3O7 |
| |
Authors: | G Roth G Heger B Renker J Pannetier V Caignaert M Hervieu B Raveau |
| |
Institution: | (1) Kernforschungszentrum Karlsruhe, Institut für Nukleare Festkörperphysik, Postfach 3640, D-7500 Karlsruhe, Federal Republic of Germany;(2) Université de Caen, F-14032 Caen, France;(3) Institut Laue Langevin, BP 156, F-38042 Grenoble, France;(4) Laboratoire Léon Brillouin, F-91191 Gif-sur-Yvette, France |
| |
Abstract: | Single crystal- and powder X-ray diffraction, powder neutron diffraction at room temperature and 3 K, high resolution electron microscopy and electron diffraction were used to study the crystal- and defect-structure of YBa2(Cu0.93Fe0.05)3O7. Crystals of this compound are superconducting (T
c
80 K) and appeart to be tetragonal down to at least 3 K. The structure resembles that of the undoped YBa2Cu3O7 phase with the oxygen content being very close to 7.0 and the Fe atoms preferentially occupying the Cu(1) site. A copper deficiency is shown to be present on this site too, leading to the approximate formula YBa2(Cu0.97Fe0.03)2(Cu0.86Fe0.10.04)O7. High resolution electron microscopy reveals the existence of orthorhombic micro-domains, 20–30 Å in diameter, probably due to short range ordering of oxygen atoms on the O(1) site. In view of these results the structure has to be regarded as being tetragonal only in a statistical sense. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|