title: The application of scanning transmission electron microscopy (STEM) to the study of thin anodic films on nickel and nickel-molybdenum alloys.
abstract: Anodized thin-film samples of nickel, molybdenum and a nickel-13 w/o molybdenum alloy have been analysed by scanning transmission electron microscopy, using selected area diffraction, microdiffraction and X-ray micro-analysis. Thin-film samples were obtained by ion thinning with argon and by electropolishing in acetic acid-perchloric acid. Electropolishing is the preferred technique for these studies, producing a surface with roughness on a scale of 1 nm. The anodized films on nickel and nickel 13 w/o molybdenum alloy exhibit a rugosity with a 'particle' size of 3 nm. The crystal structure of the films is similar to f.c.c. nickel oxide. Molybdenum enrichment was detected in the anodized alloy surfaces but there is no electron diffraction evidence for a crystalline molybdenum oxide. The electron diffraction pattern from anodized pure molybdenum suggests that the surface film is amorphous.
mesh_terms: D000497:Alloys; D004572:Electrolysis; D004577:Electron Probe Microanalysis; D008855:Microscopy, Electron, Scanning / Q000379:methods; D008982:Molybdenum; D009532:Nickel
chemical_list: D000497:Alloys; D009532:Nickel; D008982:Molybdenum