Amorphous Structures in the Immiscible Ag-Ni System

J. H. He; H. W. Sheng; P. J. Schilling; C.-L. Chien; E. Ma

doi:10.1103/PhysRevLett.86.2826

Amorphous Structures in the Immiscible Ag-Ni System

J. H. He, H. W. Sheng, P. J. Schilling, C.-L. Chien, and E. Ma

Phys. Rev. Lett. 86, 2826 – Published 26 March 2001

Abstract

Vapor quenching in the phase-separating Ag-Ni system creates alloys that appear homogeneously amorphous under conventional probes. However, an atomic-level structural analysis based on extended x-ray absorption fine structures in combination with reverse Monte Carlo and molecular dynamics simulations demonstrates that these new phases are characterized by nonuniform, spinodal-like structures on an extremely fine scale. This heterogeneous nature of the structure is directly responsible for the unexpectedly low heat (and temperature) of crystallization observed in calorimetric measurements.

Received 26 July 2000

DOI:https://doi.org/10.1103/PhysRevLett.86.2826

Authors & Affiliations

J. H. He¹, H. W. Sheng¹, P. J. Schilling², C.-L. Chien³, and E. Ma¹

¹Department of Materials Science and Engineering, The Johns Hopkins University, Baltimore, Maryland 21218
²Department of Mechanical Engineering, University of New Orleans, New Orleans, Louisiana 70145
³Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, Maryland 21218