Inhomogeneous Concentration Distribution in Obliquely Evaporated Fe-Cu Films

A distribution of atoms or local concentration in Fe x Cu 1- x films prepared by an oblique incident beam is discussed based on the results of the magnetization, Mössbauer effect, X-ray diffraction and simulation of a film-formation process. From these experiments, it was concluded that an inhomogeneous concentration distribution takes place in a column which is formed by oblique incidence. In each column three kinds of regions (Fe, Fe-Cu and Cu) are found, depending on the iron contents ( x ) and the incidence angles (θ). When θ is small, only an Fe-Cu region appears; this is an Fe-rich (bcc) or Cu-rich (fcc) alloy corresponding to large or small x , respectively. When θ is large, Fe and Cu regions appear instead of Fe-Cu regions; also, x affects the volume ratio of the Fe to Cu regions.