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We report a combined experimental and theoretical study of the melting curve and the structural behavior of vanadium under extreme pressure and temperature. We performed powder x-ray diffraction experiments up to 120 GPa and 4000 K, determining the phase boundary of the bcc-to-rhombohedral transition and melting temperatures at different pressures. Melting temperatures have also been established from the observation of temperature plateaus during laser heating, and the results from the density-functional theory calculations. Results obtained from our experiments and calculations are fully consistent and lead to an accurate determination of the melting curve of vanadium. These results are discussed in comparison with previous studies. The melting temperatures determined in this study are higher than those previously obtained using the speckle method, but also considerably lower than those obtained from shock-wave experiments and linear muffin-tin orbital calculations. Finally, a high-pressure high-temperature equation of state up to 120 GPa and 2800 K has also been determined.
The crystal structure of CO2 filled pure SiO2 LTA zeolite has been studied at high pressures and temperatures using synchrotron based x ray powder diffraction. Its structure consists of 13 CO2 guest molecules, 12 of them accommodated in the large alp
Vanadium dioxide (VO2) is a phase transition material that undergoes a reversible insulator-metal phase transition at ~ 68 C. Atmospheric pressure thermal oxidation (APTO) of vanadium (V) is a simple VO2 synthesis method in which V thin film is oxidi
We report a high-pressure study of tetragonal scheelite-type CaMoO4 up to 29 GPa. In order to characterize its high-pressure behavior, we have combined Raman and optical-absorption measurements with density-functional theory calculations. We have fou
We have studied the structural behavior of bismuth phosphate under compression. We performed x-ray powder diffraction measurements up to 31.5 GPa and ab initio calculations. Experiments were carried out on different polymorphs; trigonal (phase I) and
A thorough in situ characterization of materials at extreme conditions is challenging, and computational tools such as crystal structural search methods in combination with ab initio calculations are widely used to guide experiments by predicting the