CHEMICAL AND STRUCTURAL-ANALYSIS OF TIAL THIN-FILMS SPUTTER-DEPOSITEDON CARBON SUBSTRATES

Ti50Al50 thin films have been prepared by physical vapour deposition o n carbon substrates and characterized by X-ray analysis and diffractio n and by electron spectroscopies (Auger electron spectroscopy and Al K alpha X-ray photoelectron spectroscopy). Crystalline films are obtaine d after deposition at temperatures higher than 200-degrees-C or after annealing at 750-degrees-C of films deposited at room temperature. The tetragonal structure of the intermetallic TiAl is clearly identified. Auger profiles show a sharp film-substrate interface for deposition a t room temperature and give evidence of a diffusion process at higher temperatures. Oxygen and carbon are detected whatever the sputtering c onditions are. The chemical environment of Al, Ti, O and C is discusse d and the possibility of formation of ternary (perovskites or H phases ) or quaternary compounds (especially at the interface) is proposed.