Aguirre M H, Robert R, Logvinovich D, Weidenkaff A
Empa, Swiss Federal Laboratories for Materials Testing and Research, Solid State Chemistry and Catalysis, Ueberlandstr. 129, CH-8600 Dübendorf, Switzerland.
Inorg Chem. 2007 Apr 2;46(7):2744-50. doi: 10.1021/ic0623821. Epub 2007 Mar 8.
The crystal structure and the microstructure of LnCo0.95Ni0.05O3 compounds, synthesized by a soft chemistry process, were studied. Synchrotron and laboratory X-ray diffraction data of LnCo0.95Ni0.05O3 (Ln = Pr, Nd, Sm, Gd, and Dy) can be refined in the Pbnm space group (SG). The orthorhombic symmetry has been confirmed by transmission electron microscopy. The X-ray diffraction data of LaCo0.95Ni0.05O3 can be fitted with rhombohedral Rc and monoclinic I2/a SG. The comparison of experimental electron diffraction with theoretical simulation showed the monoclinic symmetry for the La compound has a better match than that of the rhombohedral symmetry. The Pr compound has shown to have a three-dimensional microdomain texture in which the orientation of the real unit cell, i.e., approximately radical2ap x radical2ap x 2ap (where ap is the lattice parameter of the aristotype Pm3m perovskite, noted with a "p" subscript), alternates in each domain in one of the three space directions.
研究了通过软化学工艺合成的LnCo0.95Ni0.05O3化合物的晶体结构和微观结构。LnCo0.95Ni0.05O3（Ln = Pr、Nd、Sm、Gd和Dy）的同步辐射和实验室X射线衍射数据可以在Pbnm空间群（SG）中进行精修。通过透射电子显微镜证实了正交对称性。LaCo0.95Ni0.05O3的X射线衍射数据可以用菱面体Rc和单斜I2/a SG进行拟合。实验电子衍射与理论模拟的比较表明，La化合物的单斜对称性比菱面体对称性具有更好的匹配度。Pr化合物显示出具有三维微畴织构，其中真实晶胞的取向，即近似为√2ap×√2ap×2ap（其中ap是原型Pm3m钙钛矿的晶格参数，用下标“p”表示），在三个空间方向之一的每个畴中交替变化。
