Two-dimensional laser-induced fluorescence imaging of a pulsed-laser deposition process of YBa2Cu3O7-x

Two-dimensional time-resolved density distributions of ground stare barium (Ba) and copper (Cu) atoms as well as ground state yttrium oxide (YO) molecules have been measured by two-dimensional laser-induced fluorescence during a pulsed-laser deposition (PLD) process of YB2Cu3O7-x. The gas phase of PLD has been investigated at ambient oxygen gas pressures between vacuum and 1 Torr. Characteristic behaviors have been observed for each of the measured ground state species. This is due tu different oxidation schemes with the ambient oxygen gas. Whereas YO molecules mainly formed near the expanding front of the ablation plume, Ba atoms immediately oxidized at the plume front. Cu atoms, however, did not react during the gas phase of PLD. In addition, a well defined boundary of the expanding front of the ablation plume has been observed at oxygen gas pressures above 100 mTorr. Measurements of density distributions of emissive Ba, Cu, and YO are also discussed. (C) 1996 American Institute of Physics.