Structural, optical absorption and luminescence properties of Nd3+ ions in NaO-NaF borate glasses

Structural and spectroscopic properties of neodymium doped sodium borate and fluoroborate glasses of composition (in mol%) (99 - X) B2O3 + XNa2O + 1Nd(2)O(3), X = 49.5, 39.5 and 29.5 and 49.5B(2)O(3) + XNa2O + (49.5 - X) NaF + 1Nd(2)O(3), X = 0 and 24.75 have been investigated using XRD, FTIR, absorption and emission spectra and decay curve. The XRD of the glasses confirm their glassy nature and the FUR spectra reveal the presence of BO3 and BO4 units along with the strong OH- groups in the glasses. The UV-vis-NIR absorption spectra were used to calculate the bonding parameters ((beta) over bar and delta), to identify the ionic/covalent nature of the glasses. The spectral intensities have been calculated by using Judd-Ofelt analysis and inturn used to estimate radiative properties such as radiative transition probabilities, radiative lifetimes, branching ratios, peak stimulated emission cross-sections. Branching ratios and stimulated emission cross-sections show that the F-4(3/2) -> I-4(11/2) transition of the glasses under investigation has the strong emission around 1060 nm. The decay from the F-4(3/2) level of Nd3+ ions is found to be single exponential. Multiphonon relaxation and quenching due to OH- groups play a governing role in the luminescence quenching of F-4(3/2) level of Nd3+ ions in the titled glasses. The results obtained are compared with reports on similar glasses. (C) 2010 Elsevier B.V. All rights reserved.