Acquisition of a Modern X-ray Powder Diffractometer to Support Researchers and Educators

通过化学研究仪器和设施：多用户（CRIF:MU）项目的奖励，来自印第安纳大学的David Giedroc教授及其同事Lyudmila Bronstein、Daniel Mindiola、Maren Pink和Sara Skrabalak将获得一台配备可变温度系统的x射线粉末衍射仪。该奖项将加强各级的研究培训和教育，特别是在以下领域的研究：(a)磁性纳米颗粒作为先进材料的构建块，(b)通过粉末x射线衍射表征光催化应用的无机固体，(c)手性盘状分子的自组装：粉末XRD用于纳米纤维和有机凝胶的结构分析，(d)用变温x射线粉末衍射研究相变，(e)固态反应的原位研究。x射线衍射仪可以精确测量分子的完整三维结构，包括键距和角度。并提供了在单晶或结晶粉末样品中一个分子相对于邻近分子的空间排列的准确信息。粉末x射线衍射（XRD）模式也可以用来阐明样品中晶体相的结构和相对丰度，它可以揭示相对于晶体衬底表面的材料薄膜的优选晶体取向（称为织构）的存在，并且XRD线宽可以提供平均晶体（或晶粒）直径的估计。此外，粉末XRD可以研究材料的极薄薄膜（100 nm）的结构，而单晶XRD不能探测这种薄膜。这里描述的研究将影响许多领域，包括有机和无机化学，以及材料化学。该仪器将成为教学和研究的一个组成部分，也将通过网络支持提供给合作者和学生。

With this award from the Chemistry Research Instrumentation and Facilities: Multi-user (CRIF:MU) program, Professor David Giedroc and colleagues Lyudmila Bronstein, Daniel Mindiola, Maren Pink and Sara Skrabalak from Indiana University will acquire an X-ray powder diffractometer equipped with a variable temperature system. The award will enhance research training and education at all levels, especially in areas of study such as (a) magnetic nanoparticles as building blocks in advanced materials, (b) characterization of inorganic solids for photocatalytic applications by powder X-ray diffraction, (c) self-assembly of chiral discotic molecules: powder XRD for structure analysis of nanofibers and organogels, (d) study of phase transitions with variable temperature X-ray powder diffraction, (e) in-situ investigations of solid state reactions, An X-ray diffractometer allows accurate and precise measurements of the full three dimensional structure of a molecule, including bond distances and angles, and provides accurate information about the spatial arrangement of a molecule relative to neighboring molecules in single crystals or in crystalline powdered samples. Powder X-ray diffraction (XRD) patterns can also be used to elucidate the structure and relative abundance of the crystalline phases in a sample, it can expose the existence of preferred crystalline orientation (called texture) of a film of a material relative to a crystalline substrate surface, and the XRD linewidth can provide an estimate of the mean crystallite (or grain) diameter. In addition, the structure of extremely thin films (100 nm) of materials can be investigated by powder-XRD whereas such films cannot be probed by single-crystal XRD. The studies described here will impact a number of areas, including organic and inorganic chemistry, as well as materials chemistry. This instrument will be an integral part of teaching as well as research and will also be available to collaborators and students via cyber-enabling.