Gutiérrez Seijas Julia, Prado-Gonjal Jesús, Ávila Brande David, Terry Ian, Morán Emilio, Schmidt Rainer
Dpto. Química Inorgánica I, Facultad CC. Químicas, Universidad Complutense de Madrid , 28040 Madrid, Spain.
Department of Physics, University of Durham , South Road, Durham DH1 3LE, United Kingdom.
Inorg Chem. 2017 Jan 3;56(1):627-633. doi: 10.1021/acs.inorgchem.6b02557. Epub 2016 Dec 21.
The series of perovskite rare-earth (RE) doped cobaltites (RE)CoO (RE = La-Dy) was prepared by microwave-assisted synthesis. The crystal structure undergoes a change of symmetry depending on the size of the RE cation. LaCoO is rhombohedral, S.G. R3̅c (No. 167), while, for the rest of the RE series (Pr-Dy), the symmetry is orthorhombic, S.G. Pnma (No. 62). The crystal structure obtained by X-ray diffraction was confirmed by high-resolution transmission electron microscopy, which yielded a good match between experimental and simulated images. It is further shown that the well-known magnetism in LaCoO, which involves a thermally induced Co (d) low spin to intermediate or high spin state transition, is strongly modified by the RE cation, and a rich variety of magnetic order has been detected across the series.
通过微波辅助合成法制备了一系列钙钛矿型稀土（RE）掺杂钴酸盐（RE）CoO（RE = La - Dy）。晶体结构会根据稀土阳离子的大小发生对称性变化。LaCoO为菱面体结构，空间群R3̅c（编号167），而对于其余的稀土系列（Pr - Dy），对称性为正交晶系，空间群Pnma（编号62）。通过X射线衍射获得的晶体结构由高分辨率透射电子显微镜证实，实验图像与模拟图像匹配良好。进一步表明，LaCoO中众所周知的磁性涉及热诱导的Co（d）低自旋到中间或高自旋态转变，这种磁性受到稀土阳离子的强烈影响，并且在整个系列中检测到了丰富多样的磁有序。
