Abstract
A series of Tm3+ doped lithium sodium barium borate glasses with following matrix compositions (50-x) B2O3-10BaO-10MgO-10Li(2)O-10Na(2)O-10LiF-xTm(2)O(3) (x=0.25, 0.5, 1.0 and 1.5 mol %) were prepared by melt-quenching technique. The structural, dielectric, optical and luminescence properties of the glasses were studied. FTIR study shows the presence of various vibrational bands and the number of bridging (N-4) and non-bridging (N-3) oxygens were calculated from the deconvoluted FTIR spectra. The frequency and temperature dependent dielectric properties were analyzed in the frequency range 1Hz-1MHz and the temperature ranges 50 400 degrees C. The UV-Visible-NIR spectrum of the glasses showed the presence of five transition peaks emerging from the ground state (H-3(6)) of Tm3+ ions. Bonding parameter showed the ionic nature exists between Tm (+ )ions and its neighbouring ligands. Judd-Ofelt parameters were calculated following the same trend as Omega(2) >Omega(6) > Omega(4) for all the prepared glasses. The emission spectra of the glasses were recorded in the visible region and exhibited a strong blue emission at 454 nm from the level D-1(2) -> F-3(4). Also, the prepared glasses have high experimental branching ratio value (similar to 0.9) which suggests that the prepared glasses can be used for blue laser application. Commission Internationale de I'Eclairage (CIE) coordinates and color correlated temperature (CCT) values (similar to 1500K) supported the application of the glasses for cool blue solid-state lighting.