Anomalous (resonant) diffuse x-ray scattering measurements of local correlations in disordered solid-solution alloys

With resonant (anomalous) x-ray scattering the x-ray scattering contrast between elements can be controlled to high-light local correlations in solid-solution alloys. For some binary solid-solution alloys, three diffuse-scattering maps allow the scattering from short-ranged chemical correlations, had the three individual pair static atomic displacements to be separated from the thermal diffuse scattering (TDS). For elements A and B that are nearly in the periodic table, the scattering contrast, f(A)-f(B), can be made positive, negative or nearly Zero by tuning the x-ray energy. This allows unprecedented sensitivity to static atomic displacements. Uncertainties in the static displacements < 0.0001 rtm or better out to the 10th shell can be achieved. Measurements on Fe-Ni-Cr binary alloys and others show systematic trends not predicted by previous measurements or theories.