Linear augmented Slater-type orbital study of Pt--5d-transition-metal alloying

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

DOI:https://doi.org/10.1103/PhysRevB.36.6396· OSTI ID:5987057

Watson, R E; Davenport, J W; Weinert, M

We have used a self-consistent density-functional theory with an augmented Slater-type-orbital basis to calculate the heats of formation, charge components, and densities of states for ordered 5d-transition-metal--platinum alloys. Crystal structures considered were CsCl, CuAu-I, AuCd, CrB, Cu/sub 3/Au, Al/sub 3/Ti, MoSi/sub 2/, and MoPt/sub 2/, though not all structures were calculated for each alloy system. Calculated heats of formation are in accord with the limited experimental data for close-packed systems; however, the ill-packed CrB structure cannot be described sufficiently well with our muffin-tin potentials. Correct phase-diagram behavior, i.e., the correct structure at a given composition and the competition between phases at different composition, is predicted. Charge transfer was inspected with use of the orbital population and Wigner-Seitz sphere counts as were two observables sensitive to charge behavior. These were the electron contact density at the nucleus and the initial-state shift of core-electron energy levels. Neither of these are simply related to the charge-transfer terms. In addition, the charge transfer does not correlate with traditional notions concerning differences in electronegativity. One complication, encountered previously in calculations for Au alloys, is that a significant component of the change in charge at an atomic site upon alloying has nothing to do with charge transfer, hybridization, or screening in the traditional chemical sense but is, instead, simply associated with the overlap of tails of charge best understood as being associated with orbitals centered on neighboring sites.

• Research Organization: Physics Department, Brookhaven National Laboratory, Upton, New York 11973-5000
• DOE Contract Number: AC02-76CH00016
• OSTI ID: 5987057
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Vol. 36:12; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104* -- Metals & Alloys-- Physical Properties
ALLOYS
ELECTRONIC STRUCTURE
ENERGY-LEVEL DENSITY
ENTHALPY
FORMATION HEAT
MUFFIN-TIN POTENTIAL
PHYSICAL PROPERTIES
PLATINUM ALLOYS
PLATINUM METAL ALLOYS
POTENTIALS
REACTION HEAT
SLATER METHOD
THERMODYNAMIC PROPERTIES