Skip to main content
Article
First-principles prediction of phase-segregating alloy phase diagrams and a rapid design estimate of their transition temperatures
Physical Review B (2007)
  • Nikolai A. Zarkevich, University of Illinois at Urbana-Champaign
  • Teck L. Tan, University of Illinois at Urbana-Champaign
  • Duane D. Johnson, University of Illinois at Urbana-Champaign
Abstract

We calculate the transition temperature versus concentration (Tc vs c) phase diagrams of several phase-segregating alloys [fcc Ca-Sr, Au-Pt, and Rh-(Pd,Cu,Ag,Au)] using a multiscale method combining first-principles calculations and Monte Carlo via the cluster expansion (CE). We study Pd-Rh, with its well-known high-T miscibility gap, to verify the method’s reliability. We predict that Ca-Sr segregates at low temperatures. We then show that a rapid estimate of Tc is obtained from enthalpies analytically derived from a CE, and, using thermodynamic integration, we determine under what circumstances this mean-field estimate is accurate compared to Monte Carlo results. Also, we discuss how an electronegativity difference of the alloying elements quickly assess when vibrational entropy effects should be included in the estimate of Tc.

Publication Date
March 21, 2007
Publisher Statement
Copyright 2007 American Physical Society. Posted with permission.
Citation Information
Nikolai A. Zarkevich, Teck L. Tan and Duane D. Johnson. "First-principles prediction of phase-segregating alloy phase diagrams and a rapid design estimate of their transition temperatures" Physical Review B Vol. 75 (2007)
Available at: http://works.bepress.com/duane_johnson/5/