6533b7dbfe1ef96bd127084a

RESEARCH PRODUCT

Theoretical and experimental study of CaWO4 and SrWO4 under pressure

Daniel ErrandoneaAlfredo SeguraAlfonso MuñozAndrés MujicaRavhi S. KumarS. RadescuPlácida Rodríguez-hernándezO. TschaunerJavier López-solanoGiuliana AquilantiCh. Ferrer-rocaJulio Pellicer-porresFrancisco Javier Manjón

subject

Phase transitionEquation of stateChemistryAb initioThermodynamicsGeneral ChemistryCondensed Matter PhysicsXANESPseudopotentialCrystallographyAb initio quantum chemistry methodsGeneral Materials ScienceDensity functional theoryBasis set

description

Abstract In this paper, we combine a theoretical study of the structural phases of CaWO 4 and SrWO 4 under high pressure along with the results of angle-dispersive X-ray diffraction (ADXRD) and X-ray absorption near-edge structure (XANES) measurements of both tungstates up to approximately 20 GPa. The theoretical study was performed within the ab initio framework of the density functional theory (DFT) using a plane-wave basis set and the pseudopotential scheme, with the generalized gradient approximation (GGA) for the exchange and correlation contribution to the energy. Under normal conditions, CaWO 4 and SrWO 4 crystallize in the scheelite structure. Our results show that in a hydrostatic environment, both compounds undergo a scheelite-to-fergusonite phase transition with increasing pressure. We present a comparison of the evolution of the structural parameters, equation of state, and of the features of the transition, finding an overall excellent agreement between the experimental and theoretical results.

yearjournalcountryeditionlanguage
2006-09-01Journal of Physics and Chemistry of Solids
https://doi.org/10.1016/j.jpcs.2006.05.011