A combined theoretical and experimental study of electronic structure and optical properties of beta-ZnMoO4 microcrystals

Autor(es)

Cavalcante, L. S. ^{[1, 2]} ; Moraes, E. ^[3] ; Almeida, M. A. P. ^[3] ; Dalmaschio, C. J. ^[3] ; Batista, N. C. ^[2] ; Varela, J. A. ^[1] ; Longo, E. ^[1] ; Li, M. Siu ^[4] ; Andres, J. ^[5] ; Beltran, A. ^[5]

Afiliação do(s) autor(es)

^[1] Univ Estadual Paulista, BR-14801907 Araraquara, SP - Brazil

^[2] Univ Estadual Piaui, CCN, Dept Quim, BR-64002150 Teresina, PI - Brazil

^[3] Univ Fed Sao Carlos, LIEC, DQ, BR-13565905 Sao Carlos, SP - Brazil

^[4] Univ Sao Paulo, IFSC, BR-13560970 Sao Carlos, SP - Brazil

^[5] Univ Jaume 1, Dept Quim Fis Analit, Castellon de La Plana 12071 - Spain

• Tipo de documento: Artigo Científico
• Fonte: Polyhedron; v. 54, p. 13-25, APR 30 2013.
• Citações Web of Science: 37

Resumo

In this paper, a combined theoretical and experimental study on the electronic structure and photoluminescence (PL) properties of beta zinc molybdate (beta-ZnMoO4) microcrystals synthesized by the hydrothermal method has been employed. These crystals were structurally characterized by X-ray diffraction (XRD), Rietveld refinement, Fourier transform Raman (FT-Raman) and Fourier transform infrared (FTIR) spectroscopies. Their optical properties were investigated by ultraviolet-visible (UV-Vis) absorption spectroscopy and PL measurements. First-principles quantum mechanical calculations based on the density functional theory at the B3LYP level have been carried out. XRD patterns, Rietveld refinement, FT-Raman and FT-IR spectra showed that these crystals have a wolframite-type monoclinic structure. The Raman and IR frequencies experimental results are in reasonable agreement with theoretically calculated results. UV-Vis absorption measurements shows an optical band gap value of 3.17 eV, while the calculated band structure has a value of 3.22 eV. The density of states indicate that the main orbitals involved in the electronic structure of beta-ZnMoO4 crystals are (O 2p-valence band and Mo 4d-conduction band). Finally, PL properties of beta-ZnMoO4 crystals are explained by means of distortions effects in octahedral {[}ZnO6] and {[}MoO6] clusters and inhomogeneous electronic distribution into the lattice with the electron density map. (C) 2013 Elsevier Ltd. All rights reserved. (AU)

• Processo FAPESP: 09/50303-4 - Propriedades ópticas e fotocatalíticas do ZnMoO4 e ZnWO4
• Beneficiário: Laécio Santos Cavalcante
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado