Synthesis and Characterization of SrFe x Mn 1–x (O,F) 3−δ Oxide (δ = 0 and 0.5) and Oxyfluoride Perovskite Films
Synthesis and Characterization of SrFe x Mn 1–x (O,F) 3−δ Oxide (δ = 0 and 0.5) and Oxyfluoride Perovskite Films
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SrFe x Mn 1âx (O,F) 3âδ 氧化物（δ = 0 和 0.5）和氟氧化钙钛矿薄膜的合成和表征
DOI：
10.1021/acs.inorgchem.0c01148
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发表时间：
2020
影响因子：
4.6
通讯作者：
May, Steven J.
中科院分区：
文献类型：
--
作者：
Wang, Jiayi;Lefler, Benjamin M.;May, Steven J.
我们报道了生长的SrFexMn1-xO2.5外延薄膜的合成和表征，并对其进行了生长后氧化和点定向氟化处理，得到了SrFexMn1-xO3和SrFexMn1-xO2.5−δFγ薄膜。我们展示了B位阳离子和阴离子组成如何影响这类钙钛矿材料的结构、电子和光学性质。X-射线衍射法表明，在SrMnO2.5中，Fe取代使c轴参数逐渐变宽。随着x的增加，在相同的氟化条件下掺入的F含量增加，在SrFeO2.5−δFγ中达到最大值。在B位混合占位的化合物中，Fe2p的光电子能谱峰在氟化后发生了移动，而Mn2p的光电子能谱峰没有变化，这表明诱导效应导致了F改变Mn和Fe键的不对称响应。电子输运测量表明，除SrFeO_3外，所有化合物都是绝缘体，并证明氟化作用提高了所有X值的电阻率。在SrFexMn1-xO2.5和SrFexMn1-xO3薄膜中，光学吸收光谱作为X的函数系统地演化，这与光学随Fe取代的变化是由电子结构中的Mn和Fe3d带的线性组合产生的物理场景一致。相反，F的掺入导致了光学响应的非线性变化，这表明在同时存在B位和阴离子位替代的材料中，对电子结构的影响更复杂。
We report the synthesis and characterization of as-grown SrFexMn1–xO2.5epitaxial films, which were also subjected to postgrowth oxidation and topotactic fluorination to obtain SrFexMn1–xO3and SrFexMn1–xO2.5−δFγfilms. We show how both the B-site cation and anion composition influence the structural, electronic, and optical properties of this family of perovskite materials. The Fe substitution of Mn in SrMnO2.5gradually expands thec-axis parameter, as indicated by X-ray diffraction. With increasingx, the F content incorporated under identical fluorination conditions increases, reaching its maximum in SrFeO2.5−δFγ. In the compounds with mixed B-site occupation, the Fe 2p photoemission peaks are shifted upon fluorination, while the Mn 2p peaks are not, suggesting inductive effects lead to asymmetric responses in how F alters the Mn and Fe bonds. Electronic transport measurements reveal all compounds are insulators, with the exception of SrFeO3, and demonstrate that fluorination increases resistivity for all values ofx. Optical absorption spectra in the SrFexMn1–xO2.5and SrFexMn1–xO3films evolve systematically as a function ofx, consistent with a physical scenario in which optical changes with Fe substitution arise from a linear combination of Mn and Fe 3d bands within the electronic structure. In contrast, the F incorporation induces nonlinear changes to the optical response, suggesting a more complex impact on the electronic structure in materials with concurrent B-site and anion site substitution.