Polarized off-specular scattering of 11B4C incorporated Fe/Si multilayers for neutron optics

For polarizing neutron mirrors it is of utmost importance to investigate the magnetic properties that leads to the polarization, especially magnetic domain sizes that usually are in the order of 1 to 50 µm. In this application, we propose to investigate polarized off-specular scattering of Fe/Si and Fe/Si + 11B4C multilayers to analyze the magnetic domains and how differently they affect the scattering and polarization in the off-specular directions. From pre-studies the 11B4C incorporated Fe/Si multilayers show great potential due to its higher reflectivity, polarization and significant reduction in magnetic coercivity. We believe that the off-specular scattering will be far less for the 11B4C incorporated samples and that we can gain important knowledge from polarization analysis on the off-specularly scattered neutrons to learn about the magnetic domains and its influence on polarization.

对于极化中子镜（polarizing neutron mirror）而言，探究其介导极化效应的磁特性至关重要，尤其是通常尺度介于1~50微米的磁畴（magnetic domain）尺寸。本研究拟针对Fe/Si多层膜与掺入¹¹B₄C的Fe/Si多层膜开展极化偏轴散射（off-specular scattering）研究，以解析磁畴结构，以及磁畴在偏轴方向上对散射过程与极化效应的差异化影响。前期研究显示，掺入¹¹B₄C的Fe/Si多层膜因具备更高的反射率、极化性能，且磁矫顽力（magnetic coercivity）显著降低，展现出优异的应用潜力。我们认为，掺入¹¹B₄C的样品其偏轴散射强度将大幅降低；通过对偏轴散射中子开展极化分析，可获取关于磁畴结构及其对极化效应影响的关键科学认知。