Polarization and resonance studies of x-ray magnetic scattering in holmium.
Polarization and resonance studies of x-ray magnetic scattering in holmium.
复制标题
钬中 X 射线磁散射的偏振和共振研究。
DOI：
10.1103/physrevb.43.5663
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发表时间：
1991
期刊：
影响因子：
--
通讯作者：
Vettier
中科院分区：
文献类型：
--
作者：
Gibbs;Grübel;Harshman;Isaacs;McWhan;Mills;Vettier
我们报告了钬磁性横截面的偏振和共振特性的 X 射线散射研究结果。在非共振状态下，我们测量了几种不同化学和磁反射的线性偏振度，并表明结果与 X 射线散射截面的非共振描述一致。当入射 X 射线能量调谐到 {ital L}{sub III} 吸收边附近时，可以观察到磁散射和共振整数谐波的大幅共振增强。针对低于和高于 {ital L}{sub III} 吸收边 250 eV 范围内的入射 X 射线能量，描述了积分磁场强度对入射 X 射线能量、X 射线动量传递和样品温度的依赖性的详细测量。此外，我们还表征了该范围内磁散射的线性 {sigma} 和 {pi} 偏振分量的能量依赖性，并将所得线形状拟合到共振截面的简单模型，包括原子轨道之间的电偶极子和四极子跃迁。线形状最显着的特征是它们的不对称性，这是由谐振和非谐振横截面的干扰造成的。据报道，在 {ital L}{sub II} 和 {ital L}{sub I} 吸收边附近调谐的入射 X 射线能量时，磁散射的较小共振增强。« less
We report the results of an x-ray-scattering study of the polarization and resonance properties of the magnetic cross section of holmium. Off resonance, we have measured the degree of linear polarization for several different chemical and magnetic reflections, and shown that the results are consistent with a nonresonant description of the x-ray-scattering cross section. When the incident x-ray energy is tuned near the {ital L}{sub III} absorption edge, large resonant enhancements of the magnetic scattering, and resonant integer harmonics, are observed. Detailed measurements of the dependence of the integrated magnetic intensity on the incident x-ray energy, on the x-ray momentum transfer, and on the sample temperature are described for incident x-ray energies in a range of 250 eV below and above the {ital L}{sub III} absorption edge. In addition, we have characterized the energy dependence of the linearly {sigma}- and {pi}-polarized components of the magnetic scattering in this range, and fitted the resulting line shapes to a simple model of the resonant cross section, including electric dipole and quadrupole transitions among atomic orbitals. The most striking feature of the line shapes is their asymmetry, which results from the interference of the resonant and nonresonant cross sections. Smaller resonant enhancements ofmore » the magnetic scattering are reported for incident x-ray energies tuned near the {ital L}{sub II} and {ital L}{sub I} absorption edges.« less