Symmetry and charge order in Fe 2 OBO 3 studied through polarized resonant x-ray diffraction
Symmetry and charge order in Fe 2 OBO 3 studied through polarized resonant x-ray diffraction
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通过偏振共振 X 射线衍射研究 Fe 2 OBO 3 的对称性和电荷顺序
DOI：
10.1103/physrevb.82.115110
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发表时间：
2010
影响因子：
3.7
通讯作者：
Bland S
中科院分区：
文献类型：
--
作者：
Bland S
键价和计算先前表明硼酸铁表现出具有整数价态的 Fe 离子的电荷顺序。同时，过渡金属氧化物通常表现出小得多的分数电荷歧化。通过在铁边进行共振 X 射线衍射，我们发现共振特征比通常在电荷有序氧化物中观察到的特征大得多。随后使用基于集群的单电子代码进行模拟。纳米级域结构阻碍精确拟合；然而，模拟证实了对角电荷顺序对称性，以及异常大的电荷歧化。我们通过全偏振分析演示了线性偏振光与非线性偏振光的转换，反之亦然。模拟表明，这种效应主要是由各向同性和各向异性散射项之间的干扰造成的。这种机制可能解释了替代系统中类似的观察结果。
Bond valence sum calculations have previously suggested that iron oxyborate exhibits charge order of the Fe ions with integervalence states. Meanwhile transition metal oxides typically show much smaller, fractional charge disproportionations. Using resonant x-ray diffraction at the ironedge, we find resonant features which are much larger than those ordinarily observed in charge ordered oxides. Simulations were subsequently performed using a cluster-based, monoelectronic code. The nanoscale domain structure prevents precise fitting; nevertheless the simulations confirm the diagonal charge order symmetry, as well as the unusually large charge disproportionation. We have demonstrated the conversion of linearly to nonlinearly polarized light and vice versa through full polarization analysis. Simulations show that this effect principally results from interference between the isotropic and anisotropic scattering terms. This mechanism is likely to account for similar observations in alternative systems.