Bland S R, Detlefs B, Wilkins S B, Beale T A W, Mazzoli C, Joly Y, Hatton P D, Lorenzo J E, Brabers V A M
Department of Physics, University of Durham, Durham DH1 3LE, UK.
J Phys Condens Matter. 2009 Dec 2;21(48):485601. doi: 10.1088/0953-8984/21/48/485601. Epub 2009 Oct 30.
Despite being one of the oldest known magnetic materials, and the classic mixed valence compound, thought to be charge ordered, the structure of magnetite below the Verwey transition is complex and the presence and role of charge order is still being debated. Here, we present resonant x-ray diffraction data at the iron K-edge on forbidden (0, 0, 2n+1)(C) and superlattice [Formula: see text] reflections. Full linear polarization analysis of the incident and scattered light was conducted in order to explore the origins of the reflections. Through simulation of the resonant spectra we have confirmed that a degree of charge ordering takes place, while the anisotropic tensor of susceptibility scattering is responsible for the superlattice reflections below the Verwey transition. We also report the surprising result of the conversion of a significant proportion of the scattered light from linear to nonlinear polarization.
尽管磁铁矿是已知最古老的磁性材料之一，也是经典的混合价化合物，被认为存在电荷有序，但在韦尔韦转变温度以下，其结构复杂，电荷有序的存在及作用仍存在争议。在此，我们展示了在铁K边对禁戒的(0, 0, 2n + 1)(C)和超晶格[公式：见正文]反射进行的共振X射线衍射数据。对入射光和散射光进行了全线性偏振分析，以探究反射的起源。通过对共振光谱的模拟，我们证实了一定程度的电荷有序发生，而磁化率散射的各向异性张量则导致了韦尔韦转变温度以下的超晶格反射。我们还报告了一个惊人的结果，即相当一部分散射光从线性偏振转换为非线性偏振。
