AN ANALYTICAL ELECTRON-DIFFRACTION TECHNIQUE FOR THE DETERMINATION OF LONG-RANGE ORDER PARAMETERS IN MULTICOMPONENT ORDERED ALLOYS

A combination of the channeling enhanced X-ray microanalysis (ALCHEMI) and the intersecting Kikuchi-line (IKL) method in transmission electron microscopy is used as a technique to determine long-range order (LRO) parameters of multi-component alloys. This technique, IKL-ALCHEMI, opens up a field of research on atomic configuration in multinary alloys with imperfect order, taking advantage of a transmission electron microscope equipped with an EDX spectrometer. An application of IKL-ALCHEMI to L10-type ordering in CuAuPd ternary alloys has successfully quantified occupation probabilities of the three elements on the two sublattices as a function of alloy composition. The result clearly shows the effective ordering interactions between first nearest neighboring pairs V(ij) to be V(CuPd) > V(CuAu) >> V(AuPd).