Otro
Order-disorder degree of self-assembled clusters: Influence on photoluminescence emission and morphology of BaxSr1-xTiO3 nanocrystals
Registration in:
Chemical Physics Letters. Amsterdam: Elsevier B.V., v. 514, n. 4-6, p. 301-306, 2011.
0009-2614
10.1016/j.cplett.2011.08.045
WOS:000295831700021
Author
Souza, A. E.
Silva, R. A.
Santos, G. T. A.
Teixeira, S. R.
Antonio, S. G.
Moreira, M. L.
Volanti, D. P.
Longo, Elson
Abstract
BaxSr1-xTiO3 was prepared by the microwave-assisted hydrothermal method. The ceramic powder was characterized by X-ray diffraction, Raman, ultraviolet-visible and photoluminescence (PL) spectroscopies and scanning electron microscopy (FE-SEM). The results confirm that the powders consist of perovskite-type cubic and tetragonal crystalline structures. The Raman data show bands characterizing a multi-phonon process, suggesting the presence of defects, due to partial Sr/Ba substitution, resulting in different distorted clusters. A broad-band PL emission (blue light region) confirms the existence of these defects, which together with the results of ultraviolet-visible spectroscopy suggests non-uniformity in band structure. The distinct morphologies observed are associated with different clusters organization during the nucleation and growth of the BaxSr1-xTiO3 nanoparticles. (C) 2011 Elsevier B. V. All rights reserved. Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)