Elastic constants and anisotropy in FeNi alloys at high pressures from first-principles calculations
2009 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 79, no 21Article in journal (Refereed) Published
The single-crystal and polycrystalline elastic constants and the elastic anisotropy in face-centered cubic and hexagonal close-packed FeNi alloys have been investigated at ultrahigh pressures by means of first-principles calculations using the exact muffin-tin orbitals method and the coherent-potential approximation. Comparisons with earlier calculations for pure Fe and experimental results are presented and discussed. We show that Ni alloying into Fe increases slightly the density and has very little effect on bulk moduli. Moreover, the relative decrease in c(44) elastic constant is much stronger in the hcp phase than in the fcc one. It is found that the elastic anisotropy is higher for face-centered cubic than for the hexagonal close-packed structure of FeNi, even though the face-centered cubic phase has a higher degree of symmetry. The anisotropy in face-centered cubic structure decreases with increasing nickel concentration while a very weak increase is observed for the hexagonal close-packed structure.
Place, publisher, year, edition, pages
2009. Vol. 79, no 21
CPA calculations, density functional theory, elastic constants, elastic, moduli, high-pressure effects, iron alloys, linear muffin-tin orbital, method, nickel alloys, earths inner-core, centered-cubic iron, generalized gradient, approximation, situ x-ray, free-energy, transition-metals, binary-alloys, hcp-iron, 300 gpa, phase
IdentifiersURN: urn:nbn:se:kth:diva-18573DOI: 10.1103/PhysRevB.79.214112ISI: 000267699200042ScopusID: 2-s2.0-67650119298OAI: oai:DiVA.org:kth-18573DiVA: diva2:336620
QC 201005252010-08-052010-08-052010-12-13Bibliographically approved