Ferron Thomas, Grabner Devin, McAfee Terry, Collins Brian
Department of Physics and Astronomy, Washington State University, Pullman, WA 99163, USA.
J Synchrotron Radiat. 2020 Nov 1;27(Pt 6):1601-1608. doi: 10.1107/S1600577520011066. Epub 2020 Sep 16.
Resonant soft X-ray scattering (RSOXS) has become a premier probe to study complex three-dimensional nanostructures in soft matter through combining the robust structural characterization of small-angle scattering with the chemical sensitivity of spectroscopy. This technique borrows many of its analysis methods from alternative small-angle scattering measurements that utilize contrast variation, but thus far RSOXS has been unable to reliably achieve an absolute scattering intensity required for quantitative analysis of domain compositions, volume fraction, or interfacial structure. Here, a novel technique to calibrate RSOXS to an absolute intensity at the carbon absorption edge is introduced. It is shown that the X-ray fluorescence from a thin polymer film can be utilized as an angle-independent scattering standard. Verification of absolute intensity is then accomplished through measuring the Flory-Huggins interaction parameter in a phase-mixed polymer melt. The necessary steps for users to reproduce this intensity calibration in their own experiments to improve the scientific output from RSOXS measurements are discussed.
共振软X射线散射（RSOXS）通过将小角散射强大的结构表征与光谱的化学敏感性相结合，已成为研究软物质中复杂三维纳米结构的首要探针。该技术借鉴了许多利用对比度变化的其他小角散射测量的分析方法，但到目前为止，RSOXS一直无法可靠地获得对畴组成、体积分数或界面结构进行定量分析所需的绝对散射强度。在此，介绍一种将RSOXS校准到碳吸收边缘绝对强度的新技术。结果表明，来自薄聚合物薄膜的X射线荧光可作为与角度无关的散射标准。然后通过测量相混合聚合物熔体中的弗洛里-哈金斯相互作用参数来完成绝对强度的验证。讨论了用户在自己的实验中重现这种强度校准以提高RSOXS测量科学产出的必要步骤。
