Recently, several new silicate polymorphs have been identified with high-pressure single crystal diffraction, which provide new insight into the properties of Earth's mantle 6-8.ĭifferent from single crystal diffraction at atmospheric pressure, high-pressure single crystal diffraction requires a pressure vessel to generate and maintain pressure during data collection. High-pressure experiments routinely reveal new polymorphs of common materials and can uncover ways to synthesize chemicals which are impossible to make at ambient conditions. Pressure is one of the major factors that influence the behavior and properties of Earth and planetary materials.
Recently there have been a number 1-5 of developments in high-pressure single crystal diffraction. Single crystal X-ray diffraction is one of the most efficient and well-established ways to determine the chemical composition and structure of a crystalline material at different experimental conditions. Representative single crystal diffraction data from an omphacite (Ca 0.51Na 0.48)(Mg 0.44Al 0.44Fe 2+ 0.14Fe 3+ 0.02)Si 2O 6 sample were collected. 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.
#Singlecrystal 2 simulate synchrotron software
The sample diffraction peaks are analyzed with the ATREX software program, and are then indexed with the RSV software program. The MARCCD area detector is calibrated with a powder diffraction pattern from LaB 6. The sample is aligned to the rotation center of the diffraction goniometer. The sample chamber should be loaded with noble gas to maintain a hydrostatic pressure environment.
BX-90 type DACs with conical-type diamond anvils and backing plates are recommended for these experiments. The DAC program at 13-BM-C is part of the Partnership for Extreme Xtallography (PX^2) project. 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.
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