ChemInform Abstract: Absorption and Emission Spectral Properties of Pr3+, Nd3+, and Eu3+ Ions in Heavy-Metal Oxide Glasses.

Abstract

The optical properties of the heavy-metal oxide glasses 70PbO.30TiO 2 , 70PbO.30CdO, and 70PbO.30TeO 2 doped with Pr 3+ , Nd 3+ , and Eu 3+ ions have been investigated. The transition energies of the absorption spectra of Pr 3+ and Nd 3+ ions are analyzed for the Racah parameters, configuration interaction terms, and spin-orbit coupling. The absorption spectral intensities of Pr 3+ and Nd 3+ ions are analyzed for the Judd-Ofelt parameters. The Judd-Ofelt parameter, Ω 2 , suggests strong covalency for the Ln-O bond in these oxide glass matrices for both Pr 3+ and Nd 3+ ions and follow the order 70PbO.30TiO 2 > 70PbO.30CdO > 70PbO.30TeO 2 . This trend has been correlated to that of oxide ion polarizabilities, which follow the same order. The radiative parameters, viz., transition probability (A), branching ratios (β R ), and stimulated emission cross sections (σ P ), for laser transitions have been obtained. The high Ω 2 for Pr 3+ leads to significantly larger σ p for the 3 P 0 → 3 F 2 transition in these glass matrices compared to those in fluoride and oxyfluoride glasses. The roomtemperature emission 1 D 2 → 3 H 4 transition of Pr 3+ is much larger in 70PbO.30TiO 2 than in the other two glass systems. The emission spectra of Pr 3+ show temperature effects due to the Boltzmann population. The red-to-orange intensity ratios in the emission spectra of Eu 3+ also support strong covalency of the Ln-O bond. The phonon side-band spectra (PSB) of Eu 3+ are correlated with the infrared spectra. The electron-phonon coupling strengths and phonon energies have been obtained in all the cases.