Local structures of polar wurtzites Zn_{1-x}Mg_{x}O studied by Raman and {67}Zn/{25}Mg NMR spectroscopies and by total neutron scattering

Simple item page
dc.creatorKim, Young-Il
dc.creatorCadars, Sylvian
dc.creatorShayib, Ramzy
dc.creatorProffen, Thomas
dc.creatorFeigerle, Charles S.
dc.creatorChmelka, Bradley F.
dc.creatorSeshadri, Ram
dc.date2008-08-04
dc.date.accessioned2026-07-07T10:18:13Z
dc.date.available2026-07-07T10:18:13Z
dc.descriptionLocal compositions and structures of Zn_{1-x}Mg_{x}O alloys have been investigated by Raman and solid-state {67}Zn/{25}Mg nuclear magnetic resonance (NMR) spectroscopies, and by neutron pair-distribution-function (PDF) analyses. The E2(low) and E2(high) Raman modes of Zn_{1-x}Mg_{x}O display Gaussian- and Lorentzian-type profiles, respectively. At higher Mg substitutions, both modes become broader, while their peak positions shift in opposite directions. The evolution of Raman spectra from Zn_{1-x}Mg_{x}O solid solutions are discussed in terms of lattice deformation associated with the distinct coordination preferences of Zn and Mg. Solid-state magic-angle-spinning (MAS) NMR studies suggest that the local electronic environments of {67}Zn in ZnO are only weakly modified by the 15% substitution of Mg for Zn. {25}Mg MAS spectra of Zn_{0.85}Mg_{0.15}O show an unusual upfield shift, demonstrating the prominent shielding ability of Zn in the nearby oxidic coordination sphere. Neutron PDF analyses of Zn_{0.875}Mg_{0.125}O using a 2x2x1 supercell corresponding to Zn_{7}MgO_{8} suggest that the mean local geometry of MgO_{4} fragments concurs with previous density functional theory (DFT)-based structural relaxations of hexagonal wurtzite MgO. MgO_{4} tetrahedra are markedly compressed along their c-axes and are smaller in volume than ZnO_{4} units by ~6%. Mg atoms in Zn_{1-x}Mg_{x}O have a shorter bond to the $c$-axial oxygen atom than to the three lateral oxygen atoms, which is distinct from the coordination of Zn. The precise structure, both local and average, of Zn_{0.875}Mg_{0.125}O obtained from time-of-flight total neutron scattering supports the view that Mg-substitution in ZnO results in increased total spontaneous polarization.
dc.description12 pages, 14 figures, 2 tables
dc.identifierhttps://arxiv.org/abs/0808.0492
dc.identifierhttp://arxiv.org/abs/0808.0492
dc.identifierPhys. Rev. B 78, 195205 (2008) (12 pages)
dc.identifierdoi:10.1103/PhysRevB.78.195205
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/174118
dc.subjectMaterials Science
dc.titleLocal structures of polar wurtzites Zn_{1-x}Mg_{x}O studied by Raman and {67}Zn/{25}Mg NMR spectroscopies and by total neutron scattering
dc.typetext

Files

Collections

arXiv