Materials Chemistry and Physics, Vol.141, No.2-3, 903-911, 2013
Thermal, vibrational and optical properties of Eu3+-doped lead fluorophosphate glasses for red laser applications
The Eu3+-doped lead fluorophosphate glasses of composition 44 P2O5 - 17 K2O - 9 Al2O3 - (24 - x) PbF2 - 6 Na2O - x Eu2O3, where x = 0.1, 0.5, 1.0 and 2.0 mol%, have been prepared by conventional melt quenching technique and are characterized through thermal, vibrational, absorption and emission spectra and decay rate measurements. Judd-Ofelt (JO) intensity parameters (Omega(lambda), lambda = 2, 4 and 6) have been evaluated from the absorption spectrum as well as emission spectrum of 1.0 mol% Eu2O3 doped glass. The JO parameters derived from the absorption spectrum have been used to calculate important radiative properties such as transition probability (A), lifetime (tau(R)), branching ratio (beta(R)) and peak stimulated emission cross-section (sigma(e)(lambda(p))) for the D-5(0) -> F-7(J) (J = 0, 1, 2, 3 and 4) transitions of the Eu3+ ions. The decay rates of the D-5(0) fluorescent level of Eu3+ ions in the title glasses are found to be single exponential for all the studied Eu3+ ion concentrations. A marginal increase in lifetime of the D-5(0) level has been noticed with increase in Eu3+ ion concentration from 0.1 mol% to 2.0 mol%. From the absorption spectra, the optical band gap energy (E-opt) and Urbach energy (Delta E) have been evaluated from their ultraviolet absorption edges. All the obtained results in the present study were reported and discussed in detail. (c) 2013 Elsevier B.V. All rights reserved.