0000000000955069

AUTHOR

M. Bouchenafa

showing 2 related works from this author

New Pressure-Induced Polymorphic Transitions of Anhydrous Magnesium Sulfate

2017

The effects of pressure on the crystal structure of the three known polymorphs of magnesium sulfate have been theoretically study by means of DFT calculations up to 45 GPa. We determined that at ambient conditions gamma MgSO4 is an unstable polymorph, which decompose into MgO and SO3, and that the response of the other two polymorphs to hydrostatic pressure is non isotropic. Additionally we found that at all pressures beta MgSO4 has a largest enthalpy than alpha MgSO4. This indicates that beta MgSO4 is thermodynamically unstable versus alpha MgSO4 and predicts the occurrence of a beta alpha phase transition under moderate compression. Our calculations also predict the existence under pressu…

Chemical Physics (physics.chem-ph)Phase transitionBulk modulusCondensed Matter - Materials ScienceMaterials scienceCoordination numberHydrostatic pressureEnthalpyfungiThermodynamicsMaterials Science (cond-mat.mtrl-sci)FOS: Physical sciences02 engineering and technologyCrystal structure021001 nanoscience & nanotechnology01 natural sciencesInorganic ChemistryPhase (matter)MetastabilityPhysics - Chemical Physics0103 physical sciences010306 general physics0210 nano-technology
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Ab initio study of the mechanical and electronic properties of scheelite-type XWO4(X = Ca, Sr, Ba) compounds

2017

The structural, mechanical, and electronic properties of scheelite-type CaWO4, SrWO4, and BaWO4 have been investigated using density-functional theory (DFT) within the generalized-gradient approximation (GGA). In particular, we have studied the effect of pressure in the crystal structure, elastic constants [Formula: see text], elastic moduli ([Formula: see text], [Formula: see text] and [Formula: see text]), and elastic anisotropy. We have also investigated the band structure of the three studied compounds and the effect of pressure in their electronic bandgap. The obtained results compare well with experimental results regarding the high-pressure (HP) behavior of the crystal structure. Th…

Materials sciencebusiness.industryBand gapAb initioThermodynamicsStatistical and Nonlinear Physics02 engineering and technologyCrystal structure021001 nanoscience & nanotechnologyCondensed Matter Physics01 natural scienceschemistry.chemical_compoundSemiconductorchemistryAb initio quantum chemistry methodsScheelite0103 physical sciences010306 general physics0210 nano-technologybusinessElectronic band structureElastic modulusInternational Journal of Modern Physics B
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