Formation of metal (Iron)-oxide nanostructures and nanocomposites by reactive sputtering and low-temperature reoxidation

Morphology and composition of nanostructured metal-oxide coating prepared by iron reactive sputtering and subsequent low-temperature oxidation in air at 50°C were studied by atomic-force microscopy (with digital processing of images), X-ray diffraction, and resistance measurements. The growth kinetics of metal-oxide nanoparticles constituting the sputtered metal-oxide composite was evaluated by the direct processing of surface AMF-images. According to the results of morphological studies after the low-temperature oxidation, the surface layer has complicated structure: the metal nanoparticles surrounded by the α-Fe2O3 oxide phase merge to extended rod-like structures (globules) sized, on the average, 100–200 nm lengthwise, 20–30 nm in diameter. This structure allows explaining the coatings’ functional properties important for their applications.