多层膜实验的中子反射率计算方法

Algorithms of experimental neutron reflectivity for multilayers

本文从Parratt迭代关系出发,讨论了粗糙界面多层膜反射率的计算方法和中子反射实验中散射矢量分辨及其在数据分析中的考虑;比较了指数项法和划分薄层法两种不同界面粗糙度处理方法的异同和使用条件,并结合CoFe/TiZr合金多层膜极化中子飞行时间反射实验数据分析,比较了不同分辨率考虑方法对应的拟合情况。结果表明:当界面粗糙度与膜层厚度相当时,划分薄层法计算反射率是较合适的算法;波长、角度分辨分别考虑法优于散射矢量整体考虑法。

Based on Parratt＇s formula, the algorithms of rough interface multilayer reflectivity and the resolution of scattering vector Q in the neutron reflection experiment are discussed. The differences and the use conditions have been described of the exponent method and the lames method, which are two algorithms to deal with the roughness of interfaces. Combined with experimental data of polarized neutron TOF reflection, the two fitting methods have been compared. The results indicate that the split lames algorithm of reflectivity is more suitable for the model in which interfacial roughness is in the order of thickness. As for resolution, the convolution considering angle or wavelength resolution is better than the convolution considering scattering vector.