The structural influence of aluminium ions on emission characteristics of Sm3+ ions in lead aluminium silicate glass system

Abstract Optical absorption and photoluminescence characteristics of Sm 3+ ions in lead silicate glasses mixed with different concentrations of Al 2 O 3 (5–10 mol%) have been investigated. From these studies, the radiative properties viz., spontaneous emission probability A , the total emission probability, the radiative lifetime τ R , the fluorescent branching ratio β of emission transition of 4 G 5/2  →  6 H 7/2 along with other transitions for Sm 3+ have been evaluated and found to be the highest for the glass mixed with 8.0 mol% of Al 2 O 3 .The IR spectral studies have indicated that Al 3+ ions do participate in the glass network with AlO 4 and AlO 6 structural units and further revealed that the concentration of octahedral aluminium ions induce bonding defects in the glass network. Such bonding defects are assumed to be responsible for low phonon losses in these glasses and lead to higher values of radiative parameters for the glass mixed with 8.0 mol% of Al 2 O 3 .