ALUMINA COATINGS ON POLYETHYLENE TEREPHTHALATE - CHARACTERIZATION ANDX-RAY PHOTOELECTRON-SPECTROSCOPY STUDY

Thin amorphous alumina coatings have been deposited on polyethylene te rephthalate (PET) by r.f. magnetron sputtering in a pure argon plasma. The study deals with the influence of the deposition parameters (plas ma pressure and r.f power) on the assembly properties. SEM micrographs show that the alumina microstructure was variable within a wide range , from dense to columnar. The O/Al ratio determined by Rutherford back scattering spectrometry (RBS) was found to increase with plasma pressu re. FTIR spectra of oxygen-rich alumina have shown that the excess oxy gen in the coatings was essentially due to hydroxyl groups. XPS analys es used to investigate the adhesion mechanism involved at the alumina/ PET interface revealed the formation of an interface including Al-O-C bonds.