2-DIMENSIONAL LASER-INDUCED FLUORESCENCE IMAGING OF A PULSED-LASER DEPOSITION PROCESS OF YBA2CU3O7-X

Two-dimensional time-resolved density distributions of ground stare ba rium (Ba) and copper (Cu) atoms as well as ground state yttrium oxide (YO) molecules have been measured by two-dimensional laser-induced flu orescence during a pulsed-laser deposition (PLD) process of YB2Cu3O7-x . The gas phase of PLD has been investigated at ambient oxygen gas pre ssures between vacuum and 1 Torr. Characteristic behaviors have been o bserved for each of the measured ground state species. This is due tu different oxidation schemes with the ambient oxygen gas. Whereas YO mo lecules mainly formed near the expanding front of the ablation plume, Ba atoms immediately oxidized at tile 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 observ ed at oxygen gas pressures above 100 mTorr. Measurements of density di stributions of emissive Ba, Cu, and YO are also discussed. (C) 1996 Am erican Institute of Physics.