论文标题
在5d2 rhenium double钙钛矿中衍射多尔
Diffraction by multipoles in a 5d2 rhenium double perovskite
论文作者
论文摘要
5d2 rhenium double perovskite ba2yreo6在低温下发现弱磁衍射峰的5d2 rhenium double perovskite ba2yreo6上的最新极化中子衍射实验。数据分析推断了偶极矩明显减少，并与抗fiferromagnet兼容的远距离顺序降低了非共线基序。为了解释实验发现，我们提出了一个模型波函数，用于从晶体场电位，库仑相互作用和自旋轨道耦合中得出的re离子，该耦合完全尊重低温有序状态的对称性。它用于以分析形式计算中子和共振增强的X射线衍射中所有多极力矩。与可用的中子衍射数据一致的最小模型可以预测到六烷基甲基的明显多极力矩，尤其是主要的电荷样四极力矩。计算出的衍射模式包含在l-边缘处的单晶X射线衍射，并更新了中子衍射，以探测所假定的基础多极阶。
A recent polarized neutron diffraction experiment on the 5d2 rhenium double perovskite Ba2YReO6 held at a low temperature uncovered weak magnetic diffraction peaks. Data analysis inferred a significantly reduced Re dipole moment, and long-range order compatible with an antiferromagnet, non-collinear motif. To interpret the experimental findings, we present a model wavefunction for Re ions derived from the crystal field potential, Coulomb interaction, and spin-orbit coupling that fully respects the symmetry of the low-temperature ordered state. It is used to calculate in analytic form all multipole moments visible in neutron and resonance enhanced x-ray diffraction. A minimal model consistent with available neutron diffraction data predicts significant multipolar moments up to the hexadecapole, and, in particular, a dominant charge-like quadrupole moment. Calculated diffraction patterns embrace single crystal x-ray diffraction at the Re L-edge, and renewed neutron diffraction, to probe the presumed underlying multipolar order.
