Structure and luminescent properties of Sm3+-doped metaphosphate glasses

Abstract This paper investigates the effects of the phosphate network topology on the luminescent properties of mixed sodium/alkaline earths metaphosphate glasses doped with Sm2O3. The glasses were obtained using the melt quenching technique and analysed preliminarily by X-ray diffraction to confirm the vitreous nature of the samples. Raman spectroscopy, density, and thermal analyses were pursued to validate the persistence of metaphosphate chains and examine dopant-induced effects on the phosphate network. The fluorescence analyses of the glasses show the regular emission lines of Sm3+ starting from the 4G5/2 energy level to the 6HJ/2 manifold with the largest transition in the red-orange part at 595 nm. An additional emission line starting from the higher excited state 4F3/2 to 6H5/2 between 520 and 540 nm was also detected with different intensities in all the studied compositions. This peculiar luminescence was correlated with the structure/topology of the glasses using the Judd-Ofelt theory together with the radiative and non-radiative properties of the host compositions.