Single-crystal elastic constants of ferromagnetic bcc Fe-based random alloys from first-principles theory

• The elastic properties of ferromagnetic Fe1-xMx (M=Al, Si, V, Cr, Mn, Co, Ni, and Rh; 0 <= x <= 0.1) random alloys in the body-centered-cubic (bcc) crystallographic phase have been studied using the all-electron exact muffin-tin orbitals method in combination with the coherent-potential approximation. The theoretical lattice parameters and the single-crystal elastic constants agree well with the available experimental data. The most significant alloying effects are found for Al, Si, and Ni additions. All elements enlarge the lattice parameter and decrease the C-11, C-12, and C' elastic constants and the bulk modulus of bcc Fe. At the same time, C-44 is found to increase with Al, Si, V, Cr, or Mn and remain nearly constant with Co, Ni, and Rh. Accordingly, the elastic anisotropy of bcc Fe increases with all alloying elements considered here. The calculated alloying effects on the single-crystal elastic constants are shown to originate from volume effects in combination with the peculiar electronic structure of bcc Fe.

Subject headings

NATURVETENSKAP  -- Fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences (hsv//eng)

Keyword

TOTAL-ENERGY CALCULATIONS

COHERENT-POTENTIAL APPROXIMATION

INITIO MOLECULAR-DYNAMICS

AUGMENTED-WAVE METHOD

IRON-NICKEL ALLOYS

AB-INITIO

MAGNETIC-PROPERTIES

ELECTRONIC-STRUCTURE

ALUMINUM-ALLOYS

SOLID-SOLUTIONS

Physics

Fysik

Publication and Content Type

ref (subject category)

art (subject category)