Anomalous small-angle scattering from nanoquasicrystalline precipitates in Zr80Pt20ribbons

Abstract

Anomalous small-angle X-ray scattering (ASAXS) profiles of Zr80Pt20ribbons have been measured at the ZrKabsorption edge. By annealing the melt-spun ribbons at 800 K, well defined SAXS patterns from nanoquasicrystals were observed, although the compositions of the quasicrystals (QC) and the amorphous matrix have previously been reported to be the same. The SAXS intensities were found to show a small anomalous effect at the ZrKedge. Contrast analysis suggested that the origin of the small-angle scattering is a small compositional fluctuation coupled with a small density difference, which enhances SAXS intensity but reduces the anomalous effect. A constant ASAXS intensity ratio for QC microstructure suggests that the ratio of the composition difference to the density difference between QC and the amorphous matrix is almost constant for the ZrPt ribbons examined here.