Influence of iron addition on the oxygen-deficient Sr0.85Bi0.15Co1−x
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- 作者：Annika K. Eriksson ; Fredrik Lindberg ; Gunnar Svensson ; Peter Svedlindh ; Paul F. Henry ; Sten-G. Eriksson ; Christopher S. Knee
- 关键词：Perovskite ; Oxygen vacancies ; Supercell ; Spin glass ; Neutron diffraction
- 刊名：Journal of Solid State Chemistry
- 出版年：2008
- 出版时间：August 2008
- 年：2008
- 卷：181
- 期：8
- 页码：2031-2040
- 全文大小：1331 K
文摘
A series of oxygen-deficient Sr0.85Bi0.15Co1−xFexO3−δ (0.0x1.0) perovskite phases were prepared using solid-state reaction. Results of neutron powder diffraction analyses show that the introduction of Fe onto the B-site severely effects the long range coherence of the oxygen vacancy ordered, I4/mmm supercell, observed for the x=0.0 sample. For x=0.1 a smaller, a=b≈ap, c≈2ap, P4/mmm supercell gives the best agreement to the diffraction data, whilst phases in the range 0.2x0.6 adopt disordered cubic perovskite structures. Pseudo-cubic, a=b≈ap, c≈ap, structures are found for x0.8. Evidence of weak superstructures, reflecting local oxygen ordering, is also obtained from electron diffraction. For all oxygen-annealed phases the average structure reverts to cubic Pm3¯m. The as-prepared samples show G-type antiferromagnetic order at room temperature. The oxygen annealed x=0.10, 0.25 and 1.0 samples display low-temperature spin-glass transitions.