{"title":"Measurable structure factors of dense dispersions containing polydisperse optically inhomogeneous particles.","authors":"Joel Diaz Maier, Katharina Gaus, Joachim Wagner","doi":"10.1107/S1600576724007957","DOIUrl":null,"url":null,"abstract":"<p><p>Here, it is investigated how optical properties of single scatterers in interacting multi-particle systems influence measurable structure factors. Both particles with linear gradients of their scattering length density and core-shell structures evoke characteristic deviations between the weighted sum 〈<i>S</i>(<i>Q</i>)〉 of partial structure factors in a multi-component system and experimentally accessible measurable structure factors <i>S</i> <sub>M</sub>(<i>Q</i>). While 〈<i>S</i>(<i>Q</i>)〉 contains only the structural information of self-organizing systems, <i>S</i> <sub>M</sub>(<i>Q</i>) is additionally influenced by the optical properties of their constituents, resulting in features such as changing amplitudes, additional peaks in the low-wavevector region or splitting of higher-order maxima, which are not related to structural reasons. It is shown that these effects can be systematically categorized according to the qualitative behaviour of the form factor in the Guinier region, which enables assessing the suitability of experimentally obtained structure factors to genuinely represent the microstructure of complex systems free from any particular model assumption. Hence, a careful data analysis regarding size distribution and optical properties of single scatterers is mandatory to avoid a misinterpretation of measurable structure factors.</p>","PeriodicalId":14950,"journal":{"name":"Journal of Applied Crystallography","volume":"57 Pt 5","pages":"1503-1513"},"PeriodicalIF":6.1000,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11460387/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Applied Crystallography","FirstCategoryId":"88","ListUrlMain":"https://doi.org/10.1107/S1600576724007957","RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2024/10/1 0:00:00","PubModel":"eCollection","JCR":"Q1","JCRName":"Biochemistry, Genetics and Molecular Biology","Score":null,"Total":0}
引用次数: 0
Abstract
Here, it is investigated how optical properties of single scatterers in interacting multi-particle systems influence measurable structure factors. Both particles with linear gradients of their scattering length density and core-shell structures evoke characteristic deviations between the weighted sum 〈S(Q)〉 of partial structure factors in a multi-component system and experimentally accessible measurable structure factors SM(Q). While 〈S(Q)〉 contains only the structural information of self-organizing systems, SM(Q) is additionally influenced by the optical properties of their constituents, resulting in features such as changing amplitudes, additional peaks in the low-wavevector region or splitting of higher-order maxima, which are not related to structural reasons. It is shown that these effects can be systematically categorized according to the qualitative behaviour of the form factor in the Guinier region, which enables assessing the suitability of experimentally obtained structure factors to genuinely represent the microstructure of complex systems free from any particular model assumption. Hence, a careful data analysis regarding size distribution and optical properties of single scatterers is mandatory to avoid a misinterpretation of measurable structure factors.
本文研究了相互作用的多粒子系统中单个散射体的光学特性如何影响可测量的结构因子。具有线性散射长度密度梯度的粒子和核壳结构都会引起多组分系统中部分结构因子加权和〈S(Q)〉与实验可测量结构因子 S M(Q)之间的特征性偏差。S M(Q)〉只包含自组织系统的结构信息,而 S M(Q)则受到其组成成分光学特性的额外影响,从而产生与结构原因无关的特征,如振幅变化、低波矢量区的额外峰值或高阶最大值的分裂。研究表明,这些效应可以根据吉尼尔区域的形式因子的定性行为进行系统分类,从而评估实验获得的结构因子是否适合真正代表复杂系统的微观结构,而不受任何特定模型假设的影响。因此,必须对单个散射体的尺寸分布和光学特性进行仔细的数据分析,以避免对可测量的结构因子产生误解。
期刊介绍:
Many research topics in condensed matter research, materials science and the life sciences make use of crystallographic methods to study crystalline and non-crystalline matter with neutrons, X-rays and electrons. Articles published in the Journal of Applied Crystallography focus on these methods and their use in identifying structural and diffusion-controlled phase transformations, structure-property relationships, structural changes of defects, interfaces and surfaces, etc. Developments of instrumentation and crystallographic apparatus, theory and interpretation, numerical analysis and other related subjects are also covered. The journal is the primary place where crystallographic computer program information is published.