Direct Observation of the Segregated Microstructures within Co-Cr Film Grains

The existence of a segregated microstructure within sputtered 4.1 µm-thick Co-22 at%Cr film grains is proved directly by high-spatial-resolution X-ray microanalysis. The results indicate the existence of grains comprising a Cr-rich core surrounded by a Co-rich ring, and an indication of Cr-enriched grain boundaries. This microstructure coincides well with the latent microstructure revealed by selective wet-etching with dilute aqua regia.