6533b835fe1ef96bd129ffd2

RESEARCH PRODUCT

Lattice dynamics of ZnAl2O4 and ZnGa2O4 under high pressure

Alessandra RomeroPlácida Rodríguez-hernándezAlfonso MuñozS. López-morenoEmil RusuDaniel ErrandoneaV. V. UrsakiFrancisco Javier Manjón

subject

Phase transitionWork (thermodynamics)Materials scienceCondensed matter physicsPhononHydrostatic pressureSpinelAb initioGeneral Physics and Astronomyengineering.materialMolecular physicssymbols.namesakeFISICA APLICADAMolecular vibrationengineeringsymbolsRaman scattering

description

In this work we present a ¿rst-principles density functional study of the vibrational properties of ZnAl2 O4 and ZnGa2 O4 as function of hydrostatic pressure. Based on our previous structural characterization of these two compounds under pressure, herewith, we report the pressure dependence on both systems of the vibrational modes for the cubic spinel structure, for the CaFe2 O4-type structure (Pnma) in ZnAl2 O4 and for marokite (Pbcm) ZnGa2 O4. Additionally we report a second order phase transition in ZnGa2 O4 from the marokite towards the CaTi2 O4-type structure (Cmcm), for which we also calculate the pressure dependence of the vibrational modes at the ¿ point. Our calculations are complemented with Raman scattering measurements up to 12 GPa that show a good overall agreement between our calculated and measured mode frequencies.

https://doi.org/10.1002/andp.201000096