Electronic structure and effective chemical and magnetic exchange interactions in bcc Fe-Cr alloys
2009 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 79, no 5, 054202- p.Article, review/survey (Refereed) Published
Electronic structure calculations are employed in order to investigate the cohesive properties (lattice parameter, enthalpy of formation, and bulk modulus) of random Fe-Cr alloys as a function of composition and magnetic state, as well as to derive the chemical and magnetic exchange interactions of the constituent atoms. The calculations predict certain anomalies in the cohesive properties of ferromagnetic alloys at a concentration of about 7 at % Cr; these anomalies may be related to the changes in Fermi-surface topology that occur with composition in this alloy system. The obtained interatomic interactions are used as parameters in the configurational (Ising) and magnetic (Heisenberg) Hamiltonians for modeling finite-temperature thermodynamic properties of the alloys. We discuss the approximations and limitations of similar modeling approaches, investigate the origin of existing difficulties, and analyze possible ways of extending the theoretical models in order to capture the essential physics of interatomic interactions in the Fe-Cr or similar alloys where magnetism plays a crucial role in the phase stability.
Place, publisher, year, edition, pages
2009. Vol. 79, no 5, 054202- p.
chromium alloys, elastic moduli, electronic structure, enthalpy, exchange interactions (electron), Fermi surface, ferromagnetic, materials, heat of formation, Heisenberg model, iron alloys, Ising, model, lattice constants, perturbation theory, coherent-potential approximation, molecular-dynamics simulations, duplex stainless-steels, short-range-order, fermi-surface, topological, transitions, spinodal decomposition, ferromagnetic iron, solid-solutions, thermodynamic properties
Condensed Matter Physics Metallurgy and Metallic Materials
IdentifiersURN: urn:nbn:se:kth:diva-18219DOI: 10.1103/PhysRevB.79.054202ISI: 000263815400034ScopusID: 2-s2.0-61549133916OAI: oai:DiVA.org:kth-18219DiVA: diva2:336265
QC 201506222010-08-052010-08-052015-06-22Bibliographically approved