A process for forming a ceramic layer comprising a compound of a metal on a deposition surface of a workpiece comprises providing a reactive gas, selecting the amounts of a vapor of the metal and ions of the metal relative to each other, generating the metal vapor, and projecting an ion beam of the metal ions. The metal vapor, the metal ions, and the reactive gas form the ceramic layer with a desired structure. The process may include the step of controlling a deposition surface temperature. In one embodiment, the metal vapor comprises zirconium vapor and the ion beam comprises zirconium ions. The relative amounts of the zirconium vapor and the zirconium ions are selected to form a zirconia ceramic layer on the deposition surface. The zirconia may have multiple crystal phases that are formed according to a predetermined ratio.