Al-coated iron particles: Synthesis, characterization and improvement of oxidation resistance

A Fluidized Bed Metal Organic Chemical Vapour Deposition (FB-MOCVD) process has been successfully applied to coat Fe particles with Al. N2 inert gas was used to transport the organometallic Al precursor (liquid triethylaluminium) inside the fluidized bed reactor whose temperature is 350 °C. XPS analyses and TEM observations have revealed the presence of a thin alumina layer surrounding the Al coating. Oxidation treatments, performed in the temperature range 350–500 °C, demonstrate that this multi-scale coating constitutes an efficient barrier to protect iron particles against oxidation. Such a treatment may be used to perform environmental barrier coatings around magnetic powders.