Simultaneous imaging and diffraction in the dynamic diamond anvil cell

• Published in: Review of scientific instruments 2022-05, Vol.93 (5)
• Main Authors: Husband, Rachel J., Hagemann, J., O’Bannon, E. F., Liermann, H. -P., Glazyrin, K., Sneed, D. T., Lipp, M. J., Schropp, A., Evans, W. J., Jenei, Zs
• Format: Article
• Language: English
• Subjects: CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; Diamond anvil cells; High pressure instruments; Phase contrast microscopy; Phase transitions; Synchrotron radiation; X-ray diffraction; X-ray imaging
• ISSN: 0034-6748; 1089-7623

The ability to visualize a sample undergoing a pressure-induced phase transition allows for the determination of kinetic parameters, such as the nucleation and growth rates of the high-pressure phase. For samples that are opaque to visible light (such as metallic systems), it is necessary to rely on x-ray imaging methods for sample visualization. Here, we present an experimental platform developed at beamline P02.2 at the PETRA III synchrotron radiation source, which is capable of performing simultaneous x-ray imaging and diffraction of samples that are dynamically compressed in piezo-driven diamond anvil cells. This setup utilizes a partially coherent monochromatic x-ray beam to perform lensless phase contrast imaging, which can be carried out using either a parallel- or focused-beam configuration. The capabilities of this platform are illustrated by experiments on dynamically compressed Ga and Ar. Melting and solidification were identified based on the observation of solid/liquid phase boundaries in the x-ray images and corresponding changes in the x-ray diffraction patterns collected during the transition, with significant edge enhancement observed in the x-ray images collected using the focused-beam. These results highlight the suitability of this technique for a variety of purposes, including melt curve determination.