This work demonstrates the advantage of spin-contrast-variation neutron reflectivity (NR) for the structure analysis of a buried interface in a bilayer film comprising organic and inorganic layers of acrylic urethane resin and methylated silica (MePDS), derived from methyl-group-substituted perhydropolysilazane. As the proton polarization P_H changed from 0 to ±24%, the NR curve of the bilayer film varied significantly. These NR curves were not reproduced using global fitting with a standard bilayer model. The oscillation in the NR curve at P_H = −24% was shifted slightly and non-negligibly from the fitting curve using the best-fit structure parameters for the curve at P_H = 0%. It was found from the shift of the oscillation that the density of the MePDS layer decreased within several nanometres of the interface, but the resin did not permeate the low-density MePDS layer.

中文翻译：

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利用自旋对比度变化中子反射率对有机层和多孔无机层之间的掩埋界面进行结构分析

这项工作证明了自旋对比度变化中子反射率 (NR) 用于对包含丙烯酸聚氨酯树脂和甲基化二氧化硅 (MePDS) 的有机和无机层的双层膜中的掩埋界面进行结构分析的优势，甲基化二氧化硅 (MePDS) 衍生自甲基-取代的全氢聚硅氮烷。随着质子极化P _H从 0 变化到 ±24%，双层膜的 NR 曲线变化很大。使用标准双层模型的全局拟合未再现这些 NR 曲线。使用P _H处曲线的最佳拟合结构参数，在P _H = -24%处 NR 曲线的振荡从拟合曲线轻微且不可忽略地偏移= 0%。从振荡的偏移发现，MePDS层的密度在界面的几纳米范围内降低，但树脂没有渗透到低密度的MePDS层中。