Laser-stimulated luminescence of yttria-stabilized cubic zirconia crystals

The kinetics of laser-stimulated luminescence (LSL) of yttria-stabilized cu bic zirconia single crystals is investigated. Excitation of ZrO2 . 9.5% Y2O 3 (100) and (110) using ns pulses of 213 nm (5.82 eV), 266 nm (4.66 eV), an d 355 nm (3.49 eV) photons produce LSL bands with Gaussian profiles and pea k maxima at 460 nm (2.69 eV), 550 nm (2.25 eV), and 600 nm (2.07 eV), respe ctively. LSL involves a single-photon process for energy densities below si milar to 1.0 MW/cm(2). Decay times vary from 0.1 to 100 mu s depending on t he excitation energy and temperature. Decay kinetics are hyperbolic indicat ing that all LSL bands result from recombination. The LSL quenches with inc reasing temperature and activation energies obtained using the Mott approxi mation are 0.10+/-0.01, 0.20+/-0.02, and 0.45+/-0.04 eV for the 2.69, 2.25, and 2.07 eV LSL bands, respectively. The various activation energies, deca y kinetics, and excitation/emission energies correspond to the presence of several emission centers which can be associated with anion vacancies. We t entatively assign these to intrinsic F centers and extrinsic F-type centers . The latter are associated with one and two Y3+ ions in the nearest neighb orhood positions. Since the normalized temperature dependencies of the deca y coefficients are similar for all the LSL bands, we suggest that recombina tion primarily involves electrons, trapped at intrinsic and extrinsic defec t sites, and mobilized holes. [S0021-8979(99)01709-0].