Spectroscopic and dielectric studies of Sm3Â + ions in lithium zinc borate glasses

In the present work, different concentrations of Sm3 + ions doped lithium zinc borate glasses (LBZnFSm: Li2CO3 + H3BO3 + ZnF2 + Sm2O3) were prepared by melt quench technique. Thermal stability, amorphous nature and vibrational modes of lithium zinc borate glasses have been studied by using differential scanning calorimetry, X-ray diffraction and Fourier transform infrared spectroscopy, respectively. Spectroscopic characterization of Sm3 +-doped lithium zinc borate glasses through absorption, excitation, emission and decay spectra has been carried out. Using absorption spectra nephelauxetic ratios, bonding parameters and energy band gap of the glass were evaluated. Judd-Ofelt (JO) intensity analysis had been performed and JO parameters were estimated for 1.0 mol.% Sm2O3 doped lithium zinc borate glass. Radiative properties such as transition probabilities, branching ratios and radiative lifetime were estimated by using JO parameters. Stimulated emission cross-sections and effective bandwidths of each transition were obtained from the luminescence spectra. The decay curves of Sm3 +-doped lithium zinc borate glasses exhibit single exponential nature for lower concentrations and gradually changes to non-exponential for higher Sm3 + concentrations. The experimental life time, quantum efficiency and donor acceptor interaction parameters were also estimated using decay curves of 4G5/2 level of Sm3 + ions in the present glasses. The non-exponential nature of the decay curves has been analyzed by Inokuti-Hirayama model indicating that ion interaction is of dipole-quadrupole nature. Dielectric studies of 0.1, 1.0 and 2.0 mol.% Sm2O3-doped glasses were undertaken and dielectric constants, Cole-Cole parameters and power-law parameters were also determined.