Influence of mixed alkalies on absorption and emission properties of Sm3+ ions in borate glasses

The present work aims to study the variation of Judd-Ofelt intensity parameters, radiative transition probabilities, absorption and emission cross sections with alkali content in three different Sm3+-doped mixed alkali borate glasses. Mixed alkali borate glasses in the composition 67H3BO3·xLi2CO3(32-x)Na2CO3·1Sm2O3, 67H3BO3·xLi2CO3(32-x)K2CO3·1Sm2O3 and 67H3BO3·xNa2CO3(32-x)K2CO3·1Sm2O3 with x=8, 12, 16, 20 and 24 mol% were prepared by quenching melts consisting of the above chemicals (850-950 °C, 1-2 h) between two brass plates. Judd-Ofelt theory is used to study the spectral properties and to calculate the radiative transition probabilities and branching ratios. The predicted radiative transition probabilities (Aed), branching ratios (β) and integrated absorption cross-sections (Σ) for certain transitions are reported. From the emission spectra, emission cross-sections (σP) are obtained for the four transitions, 4G5/2→6H5/2, 4G5/2→6H7/2, 4G5/2→6H9/2 and 4G5/2→6H11/2 of Sm3+ ion in these mixed alkali borate glasses. Optical band gaps (Eopt) and absorption edges are reported for the three Sm3+-doped mixed alkali borate glasses.