Structural modeling of Pd-Si and Fe-Zr-B amorphous alloys based on the microphase separation model

"Microphase separation" structure models were constructed for amorphous Pd8 2Si18 and Fe90Zr7B3 alloys using the reverse Monte Carlo chi (2) calculatio n. The input experimental data were atomic pair distributions obtained from these alloys by electron diffraction. The calculations were based on two i nitial structure models: (1) with local alpha -phase atomic clusters embedd ed in a dense-random-packing (DRP)-matrix and (2) with an entirely DRP stru cture. It was concluded that fee-clusters as small as 1-2 nm in size with a volume fraction less than 20% and bcc-clusters less than 1 nm with a large r volume fraction (about 40%) are distributed in the DRP-like matrices in t he Fil-Si and Fe-Zr-B alloys, respectively. The matrix structure in the Pd- Si alloy is mainly composed of the trigonal prisms surrounding Si atoms. (C ) 2001 Elsevier Science B.V. All rights reserved.