Polarization Analysis in Mössbauer Reflectometry with Synchrotron Mössbauer Source
Polarization Analysis in Mössbauer Reflectometry with Synchrotron Mössbauer Source
复制标题
使用同步加速器穆斯堡尔源进行穆斯堡尔反射计的偏振分析
DOI：
10.3390/condmat4010008
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发表时间：
2019
期刊：
影响因子：
1.7
通讯作者：
R. Rüffer
中科院分区：
文献类型：
--
作者：
M. Andreeva;R. Baulin;A. Chumakov;T. Kiseleva;R. Rüffer
利用同步辐射穆斯堡尔源（SMS）测量穆斯堡尔反射率时，对反射光进行偏振选择。共振散射辐射的偏振不同于入射波的偏振，因此穆斯堡尔反射率包含相对于SMS的π偏振旋转90°的散射分量，用于某些超精细跃迁。我们已经表明，从全反射率中选择这种旋转的π→σ分量给出了反射率的不寻常的角度依赖性，其特征在于在全外反射的临界角附近有一个峰。在共线反铁磁层间有序的情况下，反射率角曲线上的“磁”最大值实际上仅由具有这种旋转偏振的辐射形成。第一个实验的穆斯堡尔反射率与旋转偏振的选择发现预测的峰值附近的临界角。穆斯堡尔反射率谱中旋转π→σ偏振分量的测量排除了非共振电子散射的干扰，并简化了临界角附近的谱形，从而在分辨差的谱的情况下改进了数据解释。它示出的穆斯堡尔反射率与旋转偏振的选定组件的特征在于增强的表面灵敏度，确定的“平方驻波”的深度依赖性。因此，这种新方法对于研究具有复杂磁结构的表面、磁性层和多层膜具有很好的应用前景。
Polarization selection of the reflected radiation has been employed in Mössbauer reflectivity measurements with a synchrotron Mössbauer source (SMS). The polarization of resonantly scattered radiation differs from the polarization of an incident wave so the Mössbauer reflectivity contains a scattering component with 90° rotated polarization relative to the π-polarization of the SMS for some hyperfine transitions. We have shown that the selection of this rotated π→σ component from total reflectivity gives an unusual angular dependence of reflectivity characterized by a peak near the critical angle of the total external reflection. In the case of collinear antiferromagnetic interlayer ordering, the “magnetic” maxima on the reflectivity angular curve are formed practically only by radiation with this rotated polarization. The first experiment on Mössbauer reflectivity with a selection of the rotated polarization discovers the predicted peak near the critical angle. The measurement of the rotated π→σ polarization component in Mössbauer reflectivity spectra excludes the interference with non-resonant electronic scattering and simplifies the spectrum shape near the critical angle allowing for an improved data interpretation in the case of poorly resolved spectra. It is shown that the selected component of Mössbauer reflectivity with rotated polarization is characterized by enhanced surface sensitivity, determined by the “squared standing waves” depth dependence. Therefore, the new approach has interesting perspectives for investigations of surfaces, ultrathin layers and multilayers having complicated magnetic structures.
圆偏振 X 射线以及共振和非共振磁散射的出现
DOI：
--
发表时间：
2016
期刊：
影响因子：
--
作者：
Kouhei Fuchigami;Yo Sasaki;Maki Okube and Satoshi Sasaki
通讯作者：
Maki Okube and Satoshi Sasaki