Multiband analysis of photoluminescence spectra from electronically excited gas-phase species produced during laser ablation of lead oxide, zirconium oxide, titanium oxide, and lead zirconate titanate targets

The analysis of multiband/line photoluminescence spectra produced by electronically excited gas-phase species in the plasma plume, generated by impact of a KrF excimer laser beam (248 nm) on various metal oxide targets, has been carried out, and the results are reported. It was established that, at 1.1 J/cm{sup 2} in 900 mTorr of O{sub 2}, (i) Pb(I), Pb(II), and O{sub 2}{sup +} are generated from PbO(s) targets; (ii) Zr(I), Zr(II), ZrO, O{sub 2}, and O{sub 2}{sup +} from ZrO{sub 2}(s) targets; (iii) Ti(I), Ti(II), TiO, TiO{sub 2}, and O{sub 2}{sup +} from TiO{sub 2}(s) targets; and (iv) Pb(I), Pb(II), PbO, Zr(I), Zr(II), ZrO, Ti(I), Ti(II), TiO, TiO{sub 2}, O(I), O(II), O{sub 2}, and O{sub 2}{sup +} from a solid Pb(Zr{sub x}Ti{sub 1-x})O{sub 3}(PZT) target. The observation of excited oxygen species may be attributed to the presence of ambient molecular O{sub 2} and/or the oxygen-rich metal oxide and PZT targets. The much lower standard enthalpy of atomization, {Delta}H{sub a}{sup 0}, for PbO(s) and the much higher {Delta}H{sub a}{sup 0} values for ZrO{sub 2}(s) and TiO{sub 2}(s) are consistent with observing molecular metal oxide species, MO{sub n}(g), in the ablation plume from ZrO{sub 2}(s) and TiO{sub 2}(s) but observing almost exclusively atomic Pb(I) and Pb(II) from the PbO(s) target. Additionally, a detailed explanation regarding the observation of lower-charged atomic metal species and not the higher-charged (formally ionic) species is presented. Particle ejection is briefly discussed as also is the relative influence of the observed species on thin-film deposition. 30 refs., 4 figs., 8 tabs.