OPTICAL AND ELECTRON-PARAMAGNETIC-RESONANCE CHARACTERIZATION OF DY3-CRYSTALS( IN YSZ SINGLE)

Optical absorption of Dy3+ in yttria stabilized zirconia (YSZ) single crystals has been measured at temperatures between 10 and 300 K in the 200-2000 nm range in three samples with different Dy3+ concentration. The emission spectrum from the F-4(9/2) excited level in the visible and near infra-red spectra region has been measured at temperatures be tween 10 and 600 K. Determination of the Dy3+ content of the samples a llow us, by using the Judd-Ofelt (J-O) theory, to calculate from the 3 00 K spectrum the intensity parameters, transition probabilities and e mission branching ratios, which are compared with experiment. Lifetime measurements have been performed as a function of the temperature and Dy3+ concentration. Strong emission concentration quenching has been observed. Electron paramagnetic resonance of Dy3+ measured at 10 K has been interpreted by an axial spin Hamiltonian with Z parallel to[111] , g(parallel to)approximate to 17.5 and g(perpendicular to) approximat e to 8. Hyperfne structure due to the interaction with the two Dy-161 and Dy-163 isotopes has also been resolved. Narrow band excited lumine scence allow to distinguish between two different sites for this ion, which correspond to a statistical distribution of strongly perturbed o cto and heptacoordinated Dy3+ ions. (C) 1997 Elsevier Science Ltd.