Resonance effect in white X-ray magnetic diffraction of GdAl2
Resonance effect in white X-ray magnetic diffraction of GdAl2
复制标题
GdAl2白X射线磁衍射中的共振效应
DOI：
10.1107/s1600576715010699
复制
发表时间：
2015
影响因子：
6.1
通讯作者：
M. Ito
中科院分区：
文献类型：
--
作者：
H. Adachi;H. Kawata;M. Ito
利用椭圆偏振白色同步辐射和能量敏感探测器，测量了铁磁化合物GdAl2单晶样品沿散射矢量磁化后的444反射，并研究了GdAl2边缘x射线能量范围内磁化反转时衍射强度的不对称性。磁不对称对散射角或x射线能量的依赖可以理解为尖锐的近边结构的叠加，以及由电散射与共振和非共振磁散射之间的干扰产生的更广泛的分量。为了解释实验结果，提出了磁不对称的解析处理方法，并在分析过程中指出，在铁磁材料的x射线散射中，通常可以利用色散效应引起的布拉格反射的伪消光来提高磁灵敏度。本文还讨论了利用白光束进行共振x射线散射的一种非传统方法的潜力，正如本实验所清楚证明的那样。
Using elliptically polarized white synchrotron radiation and an energy-sensitive detector, the 444 reflection from a single-crystal sample of the ferromagnetic compound GdAl2 magnetized along the scattering vector has been measured, and the asymmetry of the diffraction intensity upon the magnetization reversal has been studied in the X-ray energy range across the Gd LII edge. The dependence of the magnetic asymmetry on the scattering angle or on the X-ray energy is understood as the superposition of the sharp near-edge structure and the much broader component arising from the interference between the electric scattering and the resonant and nonresonant magnetic scattering, respectively. To interpret the experimental results, an analytical treatment of the magnetic asymmetry is developed, and in the course of the analysis it is pointed out that in general the pseudo-extinction of the Bragg reflection due to the dispersion effects can be utilized as a technique to raise the magnetic sensitivity in the X-ray scattering from ferromagnetic materials. The potential of an unconventional approach to the resonant X-ray scattering using a white beam, as is clearly demonstrated by the present experiment, is also discussed.