6533b837fe1ef96bd12a305f
RESEARCH PRODUCT
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subject
Phase transitionWolframiteMaterials scienceCondensed matter physics02 engineering and technologyengineering.material021001 nanoscience & nanotechnologyCondensed Matter Physics01 natural sciencessymbols.namesakeElectrical resistivity and conductivityPhase (matter)0103 physical sciencesX-ray crystallographyengineeringsymbolsGeneral Materials ScienceOrthorhombic crystal system010306 general physics0210 nano-technologyRaman spectroscopyMonoclinic crystal systemdescription
Abstract The structural stability and physical properties of CrVO4 under compression were studied by x-ray diffraction, Raman spectroscopy, optical absorption, resistivity measurements, and ab initio calculations up to 10 GPa. High-pressure x-ray diffraction and Raman measurements show that CrVO4 undergoes a phase transition from the ambient pressure orthorhombic CrVO4-type structure (Cmcm space group, phase III) to the high-pressure monoclinic CrVO4-V phase, which is proposed to be isomorphic to the wolframite structure. Such a phase transition (CrVO4-type → wolframite), driven by pressure, also was previously observed in indium vanadate. The crystal structure of both phases and the pressure dependence in unit-cell parameters, Raman-active modes, resistivity, and electronic band gap, are reported. Vanadium atoms are sixth-fold coordinated in the wolframite phase, which is related to the collapse in the volume at the phase transition. Besides, we also observed drastic changes in the phonon spectrum, a drop of the band-gap, and a sharp decrease of resistivity. All the observed phenomena are explained with the help of first-principles calculations.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2020-06-19 | Journal of Physics: Condensed Matter |