0000000000281665

AUTHOR

Antonino Marco Saitta

showing 2 related works from this author

Sixfold coordinated phosphorus by oxygen in AlPO4 quartz homeotype under high pressure.

2007

International audience; AlPO4 belongs to the berlinite quartz homeotype family, which has been the subject of intense high pressure research triggered by the supposed existence of reversible pressure induced amorphization. New x-ray diffraction experiments, complemented with ab initio calculations, demonstrate the existence of two high pressure crystalline polymorphs and show that AlPO4 share the same two stage densification mechanism as silica. In first place a compact hexagonal sublattice of oxygen atoms is formed. In a second step the cations redistribute in the interstices giving rise to a monoclinic distorted CaCl2 phase. The most outstanding feature of the new phase is that phosphorou…

DiffractionMaterials scienceInorganic chemistrychemistry.chemical_element02 engineering and technology010403 inorganic & nuclear chemistry01 natural sciencesOxygenAb initio quantum chemistry methodsStructural Biology0103 physical sciences[CHIM]Chemical SciencesGeneral Materials Science010306 general physicsQuartzBerliniteMechanical EngineeringPhosphorusGeneral ChemistryCondensed Matter Physics021001 nanoscience & nanotechnology0104 chemical sciencesCrystallographychemistryMechanics of MaterialsClose relationshipHigh pressure0210 nano-technologyMonoclinic crystal system
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Vibrational properties of delafossiteCuGaO2at ambient and high pressures

2005

In this paper we investigate the vibrational properties of $\mathrm{Cu}\mathrm{Ga}{\mathrm{O}}_{2}$ delafossite by means of Raman experiments and ab initio calculations. Both investigations have been performed at ambient pressure and also at high pressure. The two Raman-active modes have frequencies ${w}_{{E}_{g}}=368\ifmmode\pm\else\textpm\fi{}1\phantom{\rule{0.3em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}1}$ and ${w}_{{A}_{1g}}=729\ifmmode\pm\else\textpm\fi{}1\phantom{\rule{0.3em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}1}$, and pressure coefficients $2.78\ifmmode\pm\else\textpm\fi{}0.03\phantom{\rule{0.3em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}1}∕\mathrm{GPa}$ $({E}_{g})$ and $4.64\ifmmode\pm\else\text…

PhysicsPhase transitionPhononDynamical instability02 engineering and technologyengineering.material021001 nanoscience & nanotechnologyCondensed Matter Physics01 natural sciencesElectronic Optical and Magnetic MaterialsDelafossitesymbols.namesakeAb initio quantum chemistry methodsHigh pressure0103 physical sciencesengineeringsymbolsAtomic physics010306 general physics0210 nano-technologyRaman spectroscopyPhysical Review B
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