NpRhGa_5和NpCoGa_5的共振X射线散射研究
Resonant x-ray scattering study of NpRhGa_5 and NpCoGa_5
摘要：
用共振X射线散射（RXS）方法研究了反铁磁镎化合物NpCoGa_5和NpRhGa_5在Np M_4和Ga K边的结构.在两个边缘的Neel温度以下观察到磁偶极子特征的大共振信号。在Np边缘的信号证实了先前从中子衍射确定的行为，即在NpCoGa_{5}中沿着[001]的矩和在NpRhGa_5中从c轴方向到ab平面的矩的重新取向。在后一种材料中，在沿[010]方向施加9特斯拉的磁场时，我们观察到不同[110]型畴的布居的变化。我们还观察到一个磁偶极子信号在Ga的K-边缘，类似于报告的UGa_3的情况下，可以解释为一个半局域模型内的Ga 4p状态通过与Np 5 f价带强杂化诱导的轨道极化。对信号的定量分析表明，在两个不同Ga位上的Ga偶极与NpRhGa_5中的Np磁矩重取向密切相关。对于不同的化合物，在两个不等价的Ga位置上的信号的比率是不相同的。
英文摘要：
We report a resonant x-ray scattering (RXS) study of antiferromagnetic neptunium compounds NpCoGa_5 and NpRhGa_5 at the Np M_4 and Ga K-edges. Large resonant signals of magnetic dipole character are observed below the Neel temperatures at both edges. The signals at the Np edges confirm the behaviour determined previously from neutron diffraction, i.e. the moments along [001] in NpCoGa_{5} and in NpRhGa_5 a reorientation of the moments from the c-axis direction to the ab plane. In the latter material, on application of magnetic field of 9 Tesla along the [010] direction we observe a change in the population of different [110]-type domains. We observe also a magnetic dipole signal at the Ga K-edge, similarly to the reported UGa_3 case, that can be interpreted within a semi-localized model as an orbital polarization of the Ga 4p states induced via strong hybridization with the Np 5f valence band. Quantitative analysis of the signal shows that the Ga dipole on the two different Ga sites follows closely the Np magnetic moment reorientation in NpRhGa_5. The ratios of the signals on the two inequivalent Ga sites are not the same for the different compounds.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
