Structural refinement, Raman spectroscopy, optical and electrical properties of (Ba1-xSrx)MoO4 ceramics

Autor(es)

Ghosh, S. K. ^[1] ; Rout, S. K. ^[1] ; Tiwari, A. ^[1] ; Yadav, P. ^[1] ; Sczancoski, J. C. ^[2] ; Filho, M. G. R. ^[3] ; Cavalcante, L. S. ^[3]

Afiliação do(s) autor(es)

^[1] Birla Inst Technol, Dept Phys, Electroceram Lab, Ranchi, Bihar - India

^[2] Univ Estadual Paulista, LIEC IQ, BR-14801907 Sao Paulo - Brazil

^[3] Univ Estadual Piaui, PPGQ GERATEC, BR-64002150 Teresina, PI - Brazil

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS; v. 26, n. 11, p. 8319-8335, NOV 2015.
• Citações Web of Science: 16

Resumo

In this paper, structural refinement, Raman spectroscopy, optical and electrical properties of barium strontium molybdate {[}(Ba1-x Sr (x) )MoO4] ceramics with different (x) contents (x = 0; 0.1; 0.2; 0.3; 0.4; 0.5; 0.6; 0.7; 0.8; 0.9; and 1) were synthesized by the solid state reaction method. These ceramics were structurally characterized by X-ray diffraction (XRD), Rietveld refinement, and micro-Raman spectroscopy. The shape of the grains for these ceramics was observed by means of scanning electron microscopy (SEM) images. The optical properties were investigated using ultraviolet-visible (UV-Vis) absorption spectroscopy and photoluminescence (PL) measurements. The dielectric and ferroelectric properties were analyzed by permittivity (epsilon(r)), loss tangent (tan delta) and polarization versus electric field (P-E) hysteresis loop. XRD patterns, Rietveld refinement, and micro-Raman spectra showed that all ceramics are monophasic with a scheelite-type tetragonal structure. A decreased of lattice parameters and unit cell volume was observed with the increase of Sr2+ ions into BaMoO4 lattice. Rietveld data were employed to model the {[}BaO8], {[}SrO8] and {[}MoO4] clusters in the tetragonal lattices. The SEM images indicate that increased x content promotes a decrease in the grain size and modifications in the shape. UV-Vis spectra indicated a decrease in the optical band gap values with an increase in x content in the (Ba1-x Sr (x) )MoO4 ceramics. PL emissions exhibit a non-linear behavior to increase or decrease with the increase of Sr2+ ions in the tetragonal lattices, when excited by a wavelength of 350 nm. The P-E decreases along with slim hysteresis loop towards higher Sr2+ ions concentration. These effects are correlated with decrease in lattice parameters and c/a ratio in this tetragonal lattice. The microwave dielectric constant and quality factor were measured using the method proposed by Hakki-Coleman. Temperature coefficient and quality factor of these materials were measured by vector network analyzer. (AU)

• Processo FAPESP: 12/14004-5 - Investigação das propriedades fotoluminescentes e fotocatalíticas de pós de BaWO4 e BaMoO4 puros e dopados com Mn, Cu e Zn
• Beneficiário: Júlio César Sczancoski
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado