Optical properties and energy transfer behavior from Tb3+ to Mn2+ ions in co-doped zinc strontium phosphate glasses

In this paper, we report optical properties and energy transfer behavior between Tb and Mn in zinc strontium phosphate glasses. Electron Paramagnetic Resonance spectra indicate a stronger hyperfine interaction of Mn2+–Mn2+ pairs with higher MnO concentrations. The co-existence of Tb3+ and Mn2+ ions in glasses is clearly evident in the transmittance spectra. Emission spectra show an obvious energy transfer from Tb3+ to Mn2+ ions in glasses. Based on Dexterʹs energy transfer formula and Reisfeldʹs approximation, the energy transfer mechanism was postulated to proceed via a dipolar–quadrupole interaction. The energy transfer carries out with resonant and cross-relaxation transfer modes with the understanding of Tb3+ and Mn2+ energy level diagrams. The decreasing in mean-duration time (τmean) of Tb3+ ions obtained from the decay curves make a further evidence of energy transfer from Tb3+ to Mn2+ ions in glasses.