Prototype fcc-based binary-alloy phase diagrams from tight-binding electronic-structure calculations

Journal Article · Sat Aug 15 04:00:00 EDT 1987 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.36.3161· OSTI ID:6059446

Turchi, P; Sluiter, M; de Fontaine, D

The generalized perturbation method (GPM), previously introduced to investigate the relative stability of simple and complex structures at T = 0 K for transition-metal alloys, is applied to the calculation of fcc-based order-disorder phase diagrams with the use of the cluster-variation method (CVM). Results obtained with the GPM have shown that it was possible to expand the electronic configurational contribution of the total energy, namely the ordering energy, as a sum of concentration-dependent effective cluster interactions, taking the completely disordered state as a reference medium. These interactions are computed from a simple but realistic description of the electronic structure based on the tight-binding approximation appropriate for transition-metal alloys. Calculated energies of mixing and effective interactions are then introduced into the CVM free energy, thereby leading to the calculation of prototype phase diagrams describing phase equilibrium between fcc superstructures of type L1/sub 0/ and L1/sub 2/ and the corresponding disordered phase. Electronic parameters are varied systematically and their influence on the topology of the resulting phase diagrams is studied for the first time.

• Research Organization: Department of Materials Science and Mineral Engineering, University of California, Berkeley, California 94720
• OSTI ID: 6059446
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Vol. 36:6; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

656002* -- Condensed Matter Physics-- General Techniques in Condensed Matter-- (1987-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALLOY SYSTEMS
ALLOYS
BINARY ALLOY SYSTEMS
CRYSTAL LATTICES
CRYSTAL STRUCTURE
CUBIC LATTICES
DIAGRAMS
ELECTRONIC STRUCTURE
FCC LATTICES
MATHEMATICS
ORDER-DISORDER TRANSFORMATIONS
PERTURBATION THEORY
PHASE DIAGRAMS
PHASE TRANSFORMATIONS
TOPOLOGY
TRANSITION ELEMENT ALLOYS