New Insight into the Gas Phase Reaction Dynamics in Pulsed Laser Deposition of Multi-Elemental Oxides

The gas-phase reaction dynamics and kinetics in a laser induced plasma are very much dependent on the interactions of the evaporated target material and the background gas. For metal (M) and metal–oxygen (MO) species ablated in an Ar and O(2) background, the expansion dynamics in O(2) are similar to the expansion dynamics in Ar for M(+) ions with an MO(+) dissociation energy smaller than O(2). This is different for metal ions with an MO(+) dissociation energy larger than for O(2). This study shows that the plume expansion in O(2) differentiates itself from the expansion in Ar due to the formation of MO(+) species. It also shows that at a high oxygen background pressure, the preferred kinetic energy range to form MO species as a result of chemical reactions in an expanding plasma, is up to 5 eV.