Electron diffraction and high-resolution electron microscopy study of an amorphous Pd 82 Si 18 alloy with nanoscale phase separation

摘要: A structure model of nanoscale phase separation has been proposed for a an amorphous Pd-Si alloy with the eutectic composition on basis electron diffraction and high-resolution microscopy (HREM). sputter-deposited ${\mathrm{Pd}}_{82}{\mathrm{Si}}_{18}$ film thickness about 10 nm was specially used in order to minimize effect multiple scattering. local atomic ordering sizes 1--2 observed by HREM, similar that liquid-quenched ribbon specimens. From HREM images nanodiffraction analysis, regions determined be fcc-Pd type. Atomic pair distribution function (PDF) analysis thin-film performed precise measurement haloelectron-diffraction intensity using imaging-plate technique. In inelastic part removed correction energy-loss spectroscopy. explain results nanodiffraction, PDF studies comprehensively, phase-separation constructed help reverse Monte Carlo calculation. fcc-cluster embedded dense-random-packing Pd Si finally obtained. The here is thought typical alloys near-eutectic compositions cooled under limited cooling rates.