Optical properties of Eu3+-doped antimony-oxide-based low phonon disordered matrices

Abstract

A new series of monolithic Eu2O3-doped high antimony oxide (40–80 mol%) content disordered matrices (glasses) of low phonon energy(about 600 cm−1) in the K2O–B2O3–Sb2O3 (KBS) system was prepared by the melt–quench technique. Infrared reflection spectroscopywas used to establish the low phonon energy of the glasses. Amorphicity and devitrificationof the glasses were confirmed by x-ray diffraction analysis. UV–vis absorption spectra ofEu3+ have been measured and the band positions have been justified with quantitative calculation ofthe nephelauxetic parameter and covalent bonding characteristics of the host. TheseEu2O3-doped glasses upon excitation at 393 nm radiation exhibit six emission bands in the range500–750 nm due to their low phonon energy. Of these, the magnetic dipole transition shows small Stark splitting while the electric dipole transition undergoes remarkable Stark splitting into two components. Theyhave been explained by the crystal field effect. The Judd–Ofelt parameters,Ωt = 2,4,6, were also evaluatedand the change of Ωt with the glass composition was correlated with the asymmetric effect atEu3+ ion sites and the fundamental properties like covalent character and opticalbasicity. We are the first to report the spectroscopic properties of theEu3+ ion in KBS low phonon antimony glasses.