First-principles investigations of the magnetocrystalline anisotropy in strained fcc co
Journal
Physical Review B - Condensed Matter and Materials Physics
Journal Volume
59
Journal Issue
22
Pages
14466-14472
Date Issued
1999
Author(s)
Gehring, G.A.
Abstract
First-principles calculations have been performed to evaluate the magnetocrystalline anisotropy energy as well as the phenomenologically defined anisotropy and magnetoelastic constants of strained fcc Co. We considered an applied uniaxial strain along both the [110] and [001] directions. It is found that the uniaxial strains not only induce large uniaxial and planar magnetoelastic anisotropies but also can act to suppress the cubic magnetocrystalline anisotropy. In the cubic limit, the calculated magnetoelastic coupling constant (Formula presented) and magnetocrystalline anisotropy constant (Formula presented) agree well with current experiments. The results are used to discuss the interesting behavior of the magnetic anisotropies as a function of film thickness observed recently in fcc (Formula presented) films. In particular, it is demonstrated that in the thick Co films (Formula presented) the uniaxial and in-plane anisotropies are predominantly strain induced. It is also argued that the observed abrupt transformation in the anisotropy constants at (Formula presented) film thickness may be caused by the combined effects of the dramatic change from the isotropic in-plane strains to the anisotropic ones and the increase in the strain size as the film thickness is gradually reduced. © 1999 The American Physical Society.
Type
journal article