Acquisition of a multi-purpose powder diffractometer for the X-ray facility at ASU Chemistry for use in research and education

根据化学研究仪器和设施：多用户计划（CRIF:MU）的这份合同，亚利桑那州立大学化学系将为x射线设施获得一台多用途粉末衍射仪。该衍射仪将用于以下方面的研究和教育：(1)半导体金属氢化物和金属/半金属-氢相互作用及其对化学结构和物理性质的影响的基础研究；(2)二氧化碳矿物封存机制，这对开发经济上可行的低压封存工艺很重要；(3)地界硅酸盐复杂相关系及结构化学研究(4)矿物在生物膜、沉积物和土壤中金属微量元素富集和分布中的作用，(5)铁磁性金属结构-性质关系的合成，以及(6)玻璃材料中的成核和生长事件，这对了解玻璃的物理化学和制造具有特殊性质的陶瓷很重要。x射线衍射仪可以精确地测量分子的三维结构，包括键的距离和角度，它提供了分子相对于邻近分子的空间排列的准确信息。具有扩展结构的材料的合成，如聚合物、无机固体、玻璃或凝胶，通常会产生多晶或相不纯的粉末。粉末x射线衍射（粉末XRD）是这类产品结构表征最有力的工具。粉末XRD图谱可以阐明所存在的晶体相的结构和相对丰度，它可以揭示相对于晶体基底表面的材料薄膜的优选晶向（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。这些研究将对许多领域产生影响，特别是合成化学。

With this award from the Chemistry Research Instrumentation and Facilities: Multi User program (CRIF:MU), the Department of Chemistry at Arizona State University will acquire a multi-purpose powder diffractometer for the X-ray facility. This diffractometer will be used for research and education in the study of (1) semiconductor metal hydrides and in fundamental studies of metal/semimetal-hydrogen interactions and their consequences to chemical structures and physical properties, (2) mechanisms of carbon dioxide mineral sequestration which are important for the development of economically viable low pressure sequestration processes, (3) the study of complicated phase relations and structural chemistry of silicates at the boundary between the Earth?s upper and lower mantle, (4) the role of minerals in the enrichment and distribution of metal trace elements in biofilms, sediments and soils, (5) the synthesis of structure-property relationships of ferromagnetic metals, and (6) nucleation and growth events in glass materials important for a general understanding of the physical chemistry of glasses and for manufacturing ceramics with special properties.The X-ray diffractometer allows accurate and precise measurements of the three dimensional structure of a molecule, including bond distances and angles, and it provides accurate information about the spatial arrangement of the molecule relative to the neighboring molecules. The synthesis of materials having an extended structure, such as polymers, inorganic solids, glasses, or gels, often yields a polycrystalline or phase-impure powder. Powder X-ray diffraction (Powder XRD) is the most powerful tool available for the structural characterization of such products. Powder XRD pattern can elucidate the structure and relative abundance of the crystalline phases present, 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. These studies will have an impact in a number of areas, especially synthetic chemistry.