The fcc superionic phase of ice is a key component of the warm dense water phase diagram. While a few x-ray diffraction studies, under dynamic and static compressions, have reported the stability of the fcc structure, the transition to the superionic state has not been investigated in detail. Here, a remarkable thermal volume expansion is disclosed, which is interpreted as being directly related to the superionic transition.
View Article and Find Full Text PDFThe behavior of iron carbonates at high pressures is relevant for geological processes occurring in Earth interiors. Here, cubic iron sp-carbonate Fe[CO] was synthesized in diamond anvil cell by reacting FeO and CO at 65(4) GPa and 3000(±500) K, simulating the environment of localized thermal anomalies in the mantle. The crystal structure, determined by in situ single-crystal X-ray diffraction, features pyramidal [CO] anions.
View Article and Find Full Text PDFWe present an investigation into the crystal structure of ErVO under variable pressure conditions. The high-pressure single-crystal X-ray diffraction experiments performed employing helium as the pressure medium facilitated structure refinements up to 24.1(2) GPa.
View Article and Find Full Text PDFThis work presents a study of the redox properties of CeO particles with (FeCeHS) and without (CeHS) FeO impregnation, as possible innovative catalysts for oxidation and combustion reactions as well as CO activation. The topic, therefore, is part of a broader analysis of environmental catalysis, which aims to reduce the emissions of polluting substances and improve the exploitation of energy resources, with consequent progress in the eco-friendly field. Different laboratory techniques (Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), Ultraviolet-Visible (UV-Vis), and Fourier Transform-Infrared (FT-IR) spectroscopies) point out that iron oxide is deposited on the surface of ceria, which maintains its lattice structure, although the particle morphology is slightly changed.
View Article and Find Full Text PDFWe present a high-resolution single crystal x-ray diffraction study of kagome superconductor CsV_{3}Sb_{5}, exploring its response to variations in pressure and temperature. We discover that at low temperatures, the structural modulations of the electronic superlattice, commonly associated with charge-density-wave order, undergo a transformation around p∼0.7 GPa from the familiar 2×2 pattern to a long-range-ordered modulation at wave vector q=(0,3/8,1/2).
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