Development of High Energy Resolution Anomalous X-ray Scattering Instrumentation for High-Brilliance Synchrotron Beamlines

该奖项由化学研究仪器和设施 （CRIF）计划和主要研究仪器（MRI）计划 综合活动办公室将支持制定一项 准确可靠的反常X射线衍射（AXD）光谱仪 由高能量分辨率窄带通晶体光学器件组成， 单色仪和晶体分析仪。 这是一个团队的努力， 北方伊利诺斯大学物理系的苏珊·米尼和 Timothy Graber和P. James Viccaro都是该联盟的科学家 芝加哥大学的先进辐射源（汽车）。 的 光谱仪将允许利用全能量分散， 吸收边附近原子的散射截面。 的 仪器，将安装在先进的光束线15 光子源（APS），将主要用于特定价态的静态 和时间分辨化学晶体学实验。 应用 包括对大型磁阻氧化物、表面和 软材料的界面性质和 聚合物 AXD技术将有助于解决未知的晶体结构， 以与中子衍射互补的方式， 局部探针，例如X射线吸收光谱。 AXD还将 提供了一个有用的方法来研究一个单一的元素的行为， 具有不同类型的配位几何结构的氧化态。 目前，AXD研究的能量分辨率为几个 eV，这防止了结构因子的选择性修改， 一种化合价的原子比另一种化合价的原子高。 该工具，其 高分辨率，结合高光谱 APS的辉煌，将在固态和 材料科学

This award from the Chemistry Research Instrumentation and Facilities (CRIF) Program and the Major Research Instrumentation (MRI) Program of the Office of Integrative Activities will support the development of an accurate and reliable anomalous x-ray diffraction (AXD) spectrometer consisting of a high-energy-resolution narrow-band-pass crystal-optics monochromator and crystal analyzer. This is a team effort involving Susan Mini of the Physics Department at Northern Illinois University and Timothy Graber and P. James Viccaro, both scientists at The Consortium for Advanced Radiation Sources (CARS) of The University of Chicago. The spectrometer will allow utilization of full energy dispersion in scattering cross-section of atoms near the absorption edge. The instrumentation, which will be installed on beamline 15 at the Advanced Photon Source (APS), will be used primarily for valence-specific static and time-resolved chemical crystallography experiments. Applications include studies on large magnetoresistive oxides, surfaces and interfacial properties of soft materials and time-dependent studies of polymers. The AXD technique will help solve unknown crystal structures containing mixed-valent atoms in a way complementary to neutron diffraction and local probes such as x-ray absorption spectroscopy. AXD will also provide a useful method to study the behavior of an element in a single oxidation state with different types of coordination geometry. Currently, AXD studies are carried out with energy resolution of a few eV, which prevents selective modification of the structure factor of atoms of one particular valence over another. This instrument, with its significantly higher resolution, combined with the high spectral brilliance of the APS, will have significant impact in solid-state and materials science.