MICROSTRUCTURAL CHARACTERIZATION OF FE-AL THIN-FILMS

The structural properties of thermally evaporated Al-Fe layers were studied as a function of the aluminium layer thickness delta-Al (taking values of 1, 2 and 4 nm), with an iron layer of constant thickness, delta-Fe = 30 nm. The quality and orientation of the material were examined by X-ray diffraction and transmission electron microscopy. Crystallites of alpha-Fe oriented in the (110) direction were around 7-8 nm in size for any value of delta-Al except near delta-Al = 1 nm where a mostly amorphous iron layer was obtained. It was also verified that a bilayer of composition delta-Al = 2 nm and delta-Fe = 30 nm, twice repeated, led to a two-phase metal system consisting of an amorphous component and crystalline alpha-Fe type material texturized along the (110) direction. The Fe3Al phase was also detected in the bilayer structure with delta-Al = 4 nm.