SMALL-ANGLE NEUTRON-SCATTERING STUDIES OF NANOSIZED AMORPHOUS SI-AU ALLOYS

Small-angle neutron scattering (SANS) was employed to characterize the microstructure of nanosized amorphous Si1-x alloys (0.1 less-than-or- equal-to x less-than-or-equal-to 0.3), produced by an inert gas conden sation and in situ consolidation technique. Amorphous grains are embed ded in a matrix of lower density, formed by grain boundaries and free volumes. The relative densities were found to be dependent on the aver age particle sizes and volume fractions, but independent of the alloy composition. In all samples, the SANS intensity decreases according to a power law Q-3.37 at low Q, which is attributed to a surface fractal structure of dimension D(s) = 2.63. This has been supported by a cont rast variation experiment.