Zhang Dongzhou, Dera Przemyslaw K, Eng Peter J, Stubbs Joanne E, Zhang Jin S, Prakapenka Vitali B, Rivers Mark L
Hawai'i Institute of Geophysics and Planetology, University of Hawai'i at Manoa;
Hawai'i Institute of Geophysics and Planetology, University of Hawai'i at Manoa.
J Vis Exp. 2017 Jan 16(119):54660. doi: 10.3791/54660.
In this report we describe detailed procedures for carrying out single crystal X-ray diffraction experiments with a diamond anvil cell (DAC) at the GSECARS 13-BM-C beamline at the Advanced Photon Source. The DAC program at 13-BM-C is part of the Partnership for Extreme Xtallography (PX^2) project. BX-90 type DACs with conical-type diamond anvils and backing plates are recommended for these experiments. The sample chamber should be loaded with noble gas to maintain a hydrostatic pressure environment. The sample is aligned to the rotation center of the diffraction goniometer. The MARCCD area detector is calibrated with a powder diffraction pattern from LaB6. The sample diffraction peaks are analyzed with the ATREX software program, and are then indexed with the RSV software program. RSV is used to refine the UB matrix of the single crystal, and with this information and the peak prediction function, more diffraction peaks can be located. Representative single crystal diffraction data from an omphacite (Ca0.51Na0.48)(Mg0.44Al0.44Fe0.14Fe0.02)Si2O6 sample were collected. Analysis of the data gave a monoclinic lattice with P2/n space group at 0.35 GPa, and the lattice parameters were found to be: a = 9.496 ±0.006 Å, b = 8.761 ±0.004 Å, c = 5.248 ±0.001 Å, β = 105.06 ±0.03º, α = γ = 90º.
在本报告中，我们描述了在先进光子源的GSECARS 13-BM-C光束线使用金刚石对顶砧（DAC）进行单晶X射线衍射实验的详细步骤。13-BM-C的DAC程序是极端晶体学合作项目（PX²）的一部分。推荐使用带有锥形金刚石砧和背板的BX-90型DAC进行这些实验。样品腔应充入惰性气体以维持静水压力环境。将样品对准衍射测角仪的旋转中心。使用LaB6的粉末衍射图对MARCCD面积探测器进行校准。用ATREX软件程序分析样品衍射峰，然后用RSV软件程序对其进行指标化。RSV用于精修单晶的UB矩阵，利用这些信息和峰预测功能，可以定位更多的衍射峰。收集了来自绿辉石（Ca0.51Na0.48）（Mg0.44Al0.44Fe0.14Fe0.02）Si2O6样品的代表性单晶衍射数据。数据分析得出在0.35 GPa下具有P2/n空间群的单斜晶格，晶格参数为：a = 9.496 ±0.006 Å，b = 8.761 ±0.004 Å，c = 5.248 ±0.001 Å，β = 105.06 ±0.03º，α = γ = 90º。
