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Title: Ground state searches in fcc intermetallics

A cluster expansion is used to predict the fcc ground states, i.e., the stable phases at zero Kelvin as a function of composition, for alloy systems. The intermetallic structures are not assumed, but derived regorously by minimizing the configurational energy subject to linear constraints. This ground state search includes pair and multiplet interactions which spatially extend to fourth nearest neighbor. A large number of these concentration-independent interactions are computed by the method of direct configurational averaging using a linearized-muffin-tin orbital Hamiltonian cast into tight binding form (TB-LMTO). The interactions, derived without the use of any adjustable or experimentally obtained parameters, are compared to those calculated via the generalized perturbation method extention of the coherent potential approximation within the context of a KKR Hamiltonian (KKR-CPA-GPM). Agreement with the KKR-CPA-GPM results is quite excellent, as is the comparison of the ground state results with the fcc-based portions of the experimentally-determined phase diagrams under consideration.
Authors:
;  [1] ;  [2] ;  [3]
  1. (Lawrence Berkeley Lab., CA (United States))
  2. (Massachusetts Inst. of Tech., Cambridge, MA (United States))
  3. (Nancy-1 Univ., 54 (France). Lab. de Physique du Solide)
Publication Date:
OSTI Identifier:
5846564
Report Number(s):
LBL-31831; CONF-911202--61
ON: DE92008300; CNN: 0512/88; INT-8815493
DOE Contract Number:
AC03-76SF00098
Resource Type:
Conference
Resource Relation:
Conference: Annual fall meeting of the Materials Research Society, Boston, MA (United States), 2-6 Dec 1991
Research Org:
Lawrence Berkeley Lab., CA (United States)
Sponsoring Org:
DOE; NSF; NATO; USDOE, Washington, DC (United States); National Science Foundation, Washington, DC (United States); North Atlantic Treaty Organization, Brussels (Belgium)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; INTERMETALLIC COMPOUNDS; PHASE STABILITY; ELECTRONIC STRUCTURE; GROUND STATES; HAMILTONIANS; ALLOYS; ENERGY LEVELS; MATHEMATICAL OPERATORS; QUANTUM OPERATORS; STABILITY 360102* -- Metals & Alloys-- Structure & Phase Studies; 665000 -- Physics of Condensed Matter-- (1992-)