Judd–Ofelt and photoluminescence analysis of Nd2O3-doped within host fluoroborate glass from the system B2O3–NaF–La2O3

Abstract

Undoped glass of chemical composition 70B2O3–25NaF–5La2O3 together with Nd2O3-doped samples were prepared via conventional melt and annealing procedure. The prepared glasses were investigated through photoluminescence measurements to find out their extent for the lasing application. The undoped sample reveals two UV absorption peaks while Nd2O3-doped samples show 10 well-characterized peaks in the UV–Visible range that are correlated to different transition states of Nd3+ ions. Three different bands are detected in the emission spectra at 875 nm (4F3/2 → 4I9/2), 1056 nm (4F3/2 → 4I11/2), and 1326 nm (4F3/2 → 4I13/2). The Judd–Ofelt parameters (Ω2, Ω4, Ω6) and radiative properties were estimated using the Judd–Ofelt theory. The represented data indicated that the transition line 4F3/2 → 4I11/2 is the sharpest and lowest bandwidth value than other detected transitions. The structural analysis by FTIR vibrational modes suggested that the IR absorption bands within the range 800–1200 cm−1 originate from both combined vibrations of tetrahedral (BO4) and (BO3F) groups together with (NaF4) groups beside triangular BO3 groups which are vibrating within the range 1200–1600 cm−1. The addition of Nd2O3 is assumed to cause the possible transformation of some structural B–O bonds within the range of triangular borate units referring to the possible formation of pyroborate units or similar structural groups.