The amorphous structure of immiscible FeCuAg alloys

Abstract

By means of facing target dc sputtering, an amorphous phase has been produced for immiscible FeCuAg alloys at around the central concentration of the ternary phase diagram. The radial distribution function estimated from X-ray diffraction measurements indicates that a tetrahedron is the dominant structure unit and that the average coordination number is about 11. In the extended X-ray absorption fine structure radial structure function, a clear peak is detected at the nearest neighbor distance, but the peak intensity is weaker than those for binary crystalline FeCu and FeAg alloys and no clear peak is detectable at larger distances. A hard or soft sphere dense random packing model is appropriate for the amorphous structure in these immiscible alloys.