Detection of AlO molecules produced by KrF laser-ablated Al atoms in oxygen gas and plasma environments

Abstract

Experiments have been performed to measure, in real time, the formation of AlO molecules from laser-ablated Al atoms in oxygen gas and plasma environments. The Al atom plume is generated by focusing a KrF laser (4 J/cm2) on Al metal targets or polycrystalline Al2O3 (alumina) ceramic. AlO molecule formation has been characterized by emission spectroscopy at 464.82 and 484.22 nm molecular bandheads. Time-integrated and time-resolved optical emissions have been measured of laser-ablated Al atoms interacting with oxygen or argon neutral-gas versus plasma backgrounds generated by a high-voltage capacitive discharge. Results indicate that gas/plasma-phase reactions occur between laser-ablated Al atoms and oxygen. Optimal enhancement of AlO optical emission is measured in oxygen plasmas at about 200 mTorr fill pressure. © 1995 American Institute of Physics.