Spin-crossover structural transition in the layered perovskite Gd2SrCo2O7
Spin-crossover structural transition in the layered perovskite Gd2SrCo2O7
复制标题
层状钙钛矿 Gd2SrCo2O7 中的自旋交叉结构转变
DOI：
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
M. Weller
中科院分区：
文献类型：
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作者：
P. Hickey;C. Knee;P. Henry;M. Weller
在300 ~ 973 K温度范围内，用粉末中子衍射测定了双层Ruddlesden-Popper相Gd2SrCo2O7的结构。室温结构是四边形的，并显示出P42/mnm对称的氧亚晶格的小倾斜，而不是理想的I4/mmm结构。在T580 K时，结构转变的特征是单位胞对称性降低，CoO6八面体轴向伸长明显；这种行为与八面体配位钴（III）离子的自旋交叉有关，最有可能是从中间到高自旋构型。
The structure of the double-layer Ruddlesden-Popper phase Gd2SrCo2O7 has been determined in the temperature range 300–973 K using powder neutron diffraction. The room-temperature structure is tetragonal and displays small tilts of the oxygen sublattice that are described in P42/mnm symmetry instead of the idealized I4/mmm structure. A structural transition at T580 K is characterized by reduction of unit cell symmetry and a marked axial elongation of the CoO6 octahedra; this behavior is associated with a spin crossover at the octahedrally coordinated cobalt (III) ions, most likely from an intermediate to a high spin configuration.