Persistent luminescence of Eu(2+) and Dy(3+) doped barium aluminate (BaAl(2)O(4):Eu(2+),Dy(3+)) materials

Polycrystalline Eu(2+) and Dy(3+) doped barium aluminate materials, BaAl(2)O(4):Eu(2+),Dy(3+), were prepared with solid state reactions at temperatures between 700 and 1500 degrees C. The influence of the thermal treatments on the stability, homogeneity and structure as well as to the UV-excited and persistent luminescence of the materials was investigated by X-ray powder diffraction, SEM imaging and infrared spectroscopies as well as by steady state luminescence spectroscopy and persistent luminescence decay curves, respectively. The IR spectra of the materials prepared at 250, 700, and 1500 degrees C follow the formation of BaAl(2)O(4) composition whereas the X-ray powder diffraction of compounds revealed how the hexagonal structure was obtained. The morphology of the materials at high temperatures indicated important aggregation due to sintering. The luminescence decay of the quite narrow Eu(2+) band at ca. 500 nm shows the presence of persistent luminescence after UV irradiation. The dopant (Eu(2+)) and co-clopant (Dy(3+)) concentrations affect the crystallinity and luminescence properties of the materials. (C) 2009 Elsevier B.V. All rights reserved.

CNPq Conselho Nacional de Desenvolvimento

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Cientifico e Tecnologico (CNPq)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Fundacao de Amparo A Pesquisa do Estado de Sao Paulo (FAPESP)

Rede de Nanotecnologia Molecular e de Interfaces (RENAMI)

Rede de Nanotecnologia Molecular e de Interfaces (RENAMI)

Instituto do Milenio de Materiais Complexos (IM<SUP>2</SUP>C)

Instituto do Milenio de Materiais Complexos (IM<SUP>2</SUP>C)

Graduate School of Materials Research (GSMR, Turku, Finland)

Graduate School of Materials Research (GSMR, Turku, Finland)