Reactive vapor deposition of metal oxide coatings

The reactive deposition of metal oxide coatings has been achieved using an electron beam directed vapor deposition (DVD) approach. In this approach, a transonic helium carrier gas jet has been combined with electron beam evap oration to create and efficiently transport metal vapor to a substrate. Met al oxide coatings were then produced by adding oxygen to the carrier gas. T he synthesis of multi-component oxide coatings could be achieved using eith er an alloy source or by simultaneous evaporation of metals from two or mor e sources. In the latter, the reactive carrier gas jet was used to facilita te vapor phase mixing of the evaporated fluxes, The preferred approach was found to be dependent on the vapor pressures of the individual source compo nents. When large differences between the component vapor pressures exist, multi-source evaporation is preferred. Results are reported for the reactiv e deposition of zirconia from a single metal source and reactive deposition of yttria stabilized zirconia from two metal sources (Y and Zr). The phase and morphology are similar to those found in similar coating compositions created by the evaporation of a pre-compounded oxide. Very good composition al uniformity in the binary metal oxide films has been observed. Vapor tran sport modeling is used to explore the origin of the composition uniformity. (C) 2001 Elsevier Science B.V. All rights reserved.