Synthesis and characterization of metal oxide multilayers obtained via MOCVD as protective coatings of graphite against oxidation

Zirconia (ZrO 2 ) titania (TiO 2 ) and alumina (Al 2 O 3 ) thin films were deposited on a graphite substrate both in mono- and in multi-layer systems, using the metal organic chemical vapor deposition technique, to test their practical qualities as protective coatings against oxidation at high temperatures. The depositions were performed using a hot wall reactor at reduced pressure (0.6 Torr) in the temperature range 350–500 °C, using, as precursors, (η 5 -C 5 H 5 ) 2 Zr(CH 2 C(CH 3 ) 3 ) 2 , Ti(OCH(CH 3 ) 2 ) 4 , and (CH 3 CH 2 ) 2 Al(OCCH 3 CHCCH 3 O), respectively. Surface and topographical analysis of the deposits using X-ray photoelectron spectroscopy, X-ray diffraction and scanning electron microscopy techniques as well as thermogravimetric measurements (TG and DTA) in an oxygen flux of mono- and multi-layer systems are reported and examined.