title: Optical absorption and photoluminescence properties of Er3+ doped mixed alkali borate glasses.
abstract: An investigations of the optical absorption and fluorescence spectra of 0.2 mol% Er2O3 in mixed alkali borate glasses of the type 67.8B2O3 x xLi2O(32-x)Na2O, 67.8B2O3 x xLi2O(32-x)K2O and 67.8B2O3 x xNa2O(32-x)K2O (where x = 8, 12, 16, 20 and 24) are presented. The glasses were obtained by quenching melts consisting of H3BO3, Li2CO3, Na2CO3, K2CO3 and Er2O3 (950-1100 degrees C, 1.5-2 h) between two brass plates. Spectroscopic parameters like Racah (E1, E2 and E3), spin-orbit (xi(4f)) and configuration interaction (alpha) parameters are deduced as function of x. Using Judd-Ofelt theory, Judd-Ofelt intensity parameters (omega2, omega4 and omega6) are obtained. Radiative and non-radiative transition rates (A(T) and W(MPR)), radiative lifetimes (tauR), branching ratios (beta) and integrated absorption cross-sections (sigma) have been computed for certain excited states of Er3+ in these mixed alkali borate glasses. Emission spectra have been studied for all the three Er3+ doped mixed alkali borate glasses. The present paper throws light on the trends observed in the intensity parameters, radiative lifetimes, branching ratios and emission cross-sections as a function of x in these borate glasses, keeping in view the effect of mixed alkalies in borate glasses.
authors.affiliation: P.G. Centre, S.V. University, Kavali 524201, AP, India. ratnakaram.yc@yahoo.co.in
authors.forename: Y C
authors.initials: YC
authors.lastname: Ratnakaram
authors.forename: A Vijaya
authors.initials: AV
authors.lastname: Kumar
authors.forename: D Tirupathi
authors.initials: DT
authors.lastname: Naidu
authors.forename: J L
authors.initials: JL
authors.lastname: Rao
mesh_terms: D000042:Absorption; D000468:Alkalies / Q000737:chemistry*; D001881:Borates / Q000737:chemistry*; D002412:Cations / Q000737:chemistry; D004871:Erbium / Q000737:chemistry*; D005898:Glass / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008163:Luminescent Measurements; D055095:Optics and Photonics; D010777:Photochemistry; D013053:Spectrophotometry
chemical_list: D000468:Alkalies; D001881:Borates; D002412:Cations; D004871:Erbium