Structural coherence between phases in Ni0.35Ag0.65 thin films

Ni0.35Ag0.65 thin films were studied by means of both x-ray absorption spec troscopy and x-ray diffraction, in the as-deposited and annealed states. Sh ort-range-order investigation has established that nickel atoms are either clustered in small pure Ni aggregates or dispersed in an Ag-rich solid solu tion. For the as-deposited and 250 degrees C annealed samples, an accurate interpretation of the diffraction spectra requires one to take into account a degree of structural coherence between these two phases, which are prefe rentially oriented with the dense planes parallel to the surface. Local ord er and long-range-order characterizations then give coherent results. The m ean size of the pure Ni aggregates increases from approximately 1 nm in the as-deposited state to 3-5 nm after a 400 degrees C anneal. The maximum Ni solubility in the Ag matrix was estimated to be around 7 at.% for these sam ples. All of the reported results-the natures of the various phases, and me an sizes, shapes and orientations of the aggregates-are discussed with rega rd to the other structural (extended x-ray absorption fine-structure, anoma lous small-angle x-ray scattering) and magnetic information.