Observation of Phase Separation in Fe/C Multilayers.

The phenomenon of phase separation in alloys and multilayers is of great fundamental and technological interest [1-4]. There are at least two important aspects in its study. First, uphill interdiffusion currents originate the metastable heterostructures in alloys [3], and they are expected to assist in the formation of atomically abrupt interfaces in artificial multilayer structures. Secondly, this process in nm-scale multilayers may be accompanied by drastic changes in their physical (e.g., mechanical, optical, magnetic, etc.) properties because their layer thicknesses are comparable with spatial interdiffusion scales.