Comparative Analysis of Hg2Br2 and Hg2BrxCl2-x Crystals Grown via PVT

In this study, we comparatively analyzed the physical properties of Hg2Br2 and Hg2BrxCl2−x crystals synthesized via physical vapor transport (PVT). Prior to crystal growth, the elemental mapping images obtained through scanning electron microscopy/energy-dispersive spectroscopy clearly showed the presence of Cl atoms (2.62%) in Hg2BrxCl2−x powder; however, Cl atoms were not detected in Hg2Br2 powder. After crystal growth by PVT, each single crystal was characterized using various analysis techniques, such as X-ray diffraction, X-ray photoelectron spectroscopy, and Raman spectroscopy. It was observed that the introduction of Cl elements into Hg2Br2 crystals strongly affected the crystallinity and Raman vibration modes. Hence, this in-depth material characterization study proposed a feasible method to screen impurities in mercury halide crystals.