Abstract

The brownmillerite phase has been studied by X-ray diffraction and Mössbauer methods. The available data on single-phase compounds with the perovskite structure in strontium ferrite SrFeO_3 – δ are analyzed. All the valence states of iron for any phase state of strontium ferrite are found to be determined by its local oxygen environment. This fact enables us to understand the regularity of transitions of iron from one valence state to another state when adding oxygen vacancies and to explain the structural states of iron in strontium ferrite, such as the single-phase and two-phase compositions. This approach is a more general case for description of all known compounds and phase combinations synthesized in SrFeO_3 – δ than the formula for single-phase structures that is considered in the literature and fit well into the scheme proposed in this work.

中文翻译：

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SrFeO 3-δ化合物中铁的氧空位和价态

摘要

已经通过X射线衍射和Mössbauer方法研究了褐锰矿相。分析了锶铁氧体SrFeO _3-δ中具有钙钛矿结构的单相化合物的可用数据。发现对于锶铁氧体的任何相态，铁的所有价态均由其局部氧环境决定。这一事实使我们能够了解添加氧空位时铁从一种价态转变为另一种态的规律性，并解释锶铁氧体中铁的结构态，例如单相和两相组成。这种方法是描述在SrFeO _{3 –δ中}合成的所有已知化合物和相组合的更一般的情况 比文献中考虑的单相结构公式更适合本工作中提出的方案。