Urushihara Daisuke, Nakajima Kenta, Nakamura Ariki, Fukuda Koichiro, Sugai Hodaka, Konishi Shinya, Tanaka Katsuhisa, Asaka Toru
Division of Advanced Ceramics, Nagoya Institute of Technology, Nagoya 466-855, Japan.
Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan.
Acta Crystallogr C Struct Chem. 2021 Jun 1;77(Pt 6):286-290. doi: 10.1107/S2053229621005258. Epub 2021 May 26.
A novel Ruddlesden-Popper-related compound, GdBaFeO, was discovered and its crystal structure was determined via single-crystal X-ray diffraction. The structure has an ordered structure of octahedra and pyramids along the c axis. GdBaFeO belongs to the tetragonal system P4/ncm, with a = 5.59040 (10) Å and c = 35.1899 (10) Å. The A-site ions in the Ruddlesden-Popper structure, i.e. Gd and Ba, exhibit an ordering along the c axis. The perfect oxygen deficiency is accommodated at the GdO layers in the proper Ruddlesden-Popper structure. Using the bond-valence-sum method, the Fe ions in the FeO octahedra and FeO pyramids represent valence states of +3 and +2.5, respectively, demonstrating a two-dimensional charge disproportionation. The corner-sharing FeO octahedra and FeO pyramids are tilted in opposite directions, with the neighbours around one axis of the simple perovskite configuration, which, using Glazer's notation, can be represented as abc/bac. In the perovskite blocks, the facing FeO pyramids across the Gd layer rotate in the same sense, which is a unique rotation feature related to oxygen deficiency.
发现了一种新型的与Ruddlesden-Popper相关的化合物GdBaFeO，并通过单晶X射线衍射确定了其晶体结构。该结构沿c轴具有八面体和金字塔的有序结构。GdBaFeO属于四方晶系P4/ncm，a = 5.59040 (10) Å，c = 35.1899 (10) Å。Ruddlesden-Popper结构中的A位离子，即Gd和Ba，沿c轴呈现有序排列。在适当的Ruddlesden-Popper结构中，完美的氧缺陷存在于GdO层。使用键价和方法，FeO八面体和FeO金字塔中的Fe离子分别代表+3和+2.5的价态，表明存在二维电荷歧化。共角的FeO八面体和FeO金字塔向相反方向倾斜，围绕简单钙钛矿构型的一个轴的相邻部分，使用Glazer符号可表示为abc/bac。在钙钛矿块中，穿过Gd层相对的FeO金字塔以相同方向旋转，这是与氧缺陷相关的独特旋转特征。
