THE COMPLEX PEROVSKITE-RELATED SUPERSTRUCTURE BA2FE2O5 SOLVED BY HREM AND CIP

被引:57
作者
ZOU, XD
HOVMOLLER, S
PARRAS, M
GONZALEZCALBET, JM
VALLETREGI, M
GRENIER, JC
机构
[1] UNIV COMPLUTENSE,FAC C QUIM,DEPT QUIM INORGAN,E-28040 MADRID,SPAIN
[2] UNIV COMPLUTENSE,FAC FARM,DEPT QUIM INORGAN & BIOINORGAN,E-28040 MADRID,SPAIN
[3] UNIV BORDEAUX 1,CHIM SOLIDE LAB,CNRS,F-33405 TALENCE,FRANCE
来源
ACTA CRYSTALLOGRAPHICA SECTION A | 1993年 / 49卷
关键词
D O I
10.1107/S0108767392007979
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
Barium ferrite Ba2Fe2O5 is a complex perovskite-related structure. The crystal is monoclinic P2(1)/c, with a = 6.969(l), b = 11.724(1), c = 23.431(5) angstrom, beta = 98.74(l)-degrees. The composition of one unit cell is Ba28Fe28O70. The structure was solved using a combination of high-resolution electron microscopy (HREM), crystallographic image processing (CIP) and electron diffraction. The structure can be described as a perovskite with 14 oxygen positions unoccupied with respect to the ABO3 stoichiometry in the monoclinic unit cell. These positions can be identified from the potential map obtained by HREM and CIP. They form two linear groups. Seven of them lie on a line along [476]m (corresponding to [110]c of perovskite), while the seven other symmetry-related positions lie along [476BAR]m (corresponding to [101]c of perovskite).
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页码:27 / 35
页数:9
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