Frenkel A I, Pease D M, Budnick J I, Shanthakumar P, Huang T
Department of Physics, Yeshiva University, New York, NY 10016, USA.
J Synchrotron Radiat. 2007 May;14(Pt 3):272-5. doi: 10.1107/S0909049507014409. Epub 2007 Apr 11.
X-ray absorption fine-structure (XAFS) data were obtained for the V K-edge for a series of anisotropic single crystals of (Cr(x)V(1-x))(2)O(3). The data and the results were compared for the as-prepared bulk single crystals (measured in fluorescence in two different orientations) and those ground to powder (measured in transmission). For the bulk single crystals, the glancing-emergent-angle (GEA) method was used to minimize fluorescence distortion. The reliability of the GEA technique was tested by comparing the polarization-weighted single-crystal XAFS data with the experimental powder data. These data were found to be in excellent agreement throughout the entire energy range. Thus, it was possible to reliably measure individual V-V contributions parallel and perpendicular to the c axis of the single crystals, i.e. those unavailable by powder data XAFS analysis. These experiments demonstrate that GEA is a premiere method for non-destructive high-photon-count in situ studies of local structure in bulk single crystals.
获得了一系列（Cr(x)V(1-x))(2)O(3)各向异性单晶的钒K边X射线吸收精细结构（XAFS）数据。将所制备的块状单晶（在两种不同取向以荧光模式测量）和研磨成粉末的单晶（以透射模式测量）的数据及结果进行了比较。对于块状单晶，采用掠出射角（GEA）方法来最小化荧光畸变。通过将偏振加权的单晶XAFS数据与实验粉末数据进行比较，测试了GEA技术的可靠性。发现在整个能量范围内这些数据非常吻合。因此，能够可靠地测量平行和垂直于单晶c轴的单个V-V贡献，即粉末数据XAFS分析无法获得的贡献。这些实验表明，GEA是用于块状单晶局部结构无损高光子计数原位研究的首要方法。
