SEGREGATION STUDIES ON EVAPORATED AND ELECTRODEPOSITED THIN-FILMS OF CR

AES with depth profiling was used to investigate the segregation in Cr evaporated and electrodeposited thin films on mild steel substrate. The evaporated samples showed a relatively pure Cr layer with a sharp interface, but were enriched with N after heating to temperatures above 400-degrees-C. In the electrodeposited samples a poorly defined interface was observed which may be ascribed to, amongst other reasons, preparation of the substrate. The formation of Cr2O3 in the top surface layer serves as an efficient barrier to Fe atom diffusion in the Cr thin film samples, thus preventing the formation of iron oxides at high temperatures.