Photoluminescence of Dy3+ and Sm3+: SiO2-Al2O3-LiF-CaF2 glasses

In this paper, we present the absorption and photoluminescence properties of Dy3+ and Sm3+ (1.0 mol%) ions doped SiO2-Al2O3-LiF-CaF2 glasses. The X-ray diffraction (XRD) and differential scanning calorimetry (DSC) profiles of these rare-earth ions doped glasses have been carried out, to confirm their structure and thermal stability. From the DSC thermograms, glass transition temperature (T-g), crystallization temperatures (T-c1 and T-c2) and melting temperature (T-m) have been evaluated. These glasses have shown strong emission and absorption bands in ultraviolet and visible region. For Dy3+ doped glass, a bright fluorescent blue emission at 482 nm (F-4(9/2)-> H-6(15/2)) and yellow emission at 574 nm (F-4(9/2)-> H-6(13/2)) have been observed, apart from (I-4(13/2)-> F-6(7/2))-> H-6(13/2) (454 nm) and F-4(9/2)-> H-6(11/2) (662 nm) two comparative weak emission transitions with 348 nm (H-6(15/2)-> M-4(15/2)+P-6(7/2)) excitation wavelength. With regard to Sm3+: glass, emission bands of (4)G(5/2)-> H-6(5/2) (563 nm), (4)G(5/2)-> H-6(7/2) (599 nm) and (4)G(5/2)-> H-6(9/2) (647 nm) have been recorded with an excitation at H-6(5/2)-> 4F(7/2) (401 nm). Of them, (4)G(5/2)-> H-6(7/2) (599 nm) has shown a bright orange emission. Upon exposure to UV radiation, Dy3+ and Sm3+ glasses have shown bright blue-yellow and orange colors, respectively, from their surfaces. (C) 2010 Elsevier B.V. All rights reserved.