L. Steinbeck et al., Itinerant-electron magnetocrystalline anisotropy energy of YCo5 and related compounds - art. no. 184431, PHYS REV B, 6318(18), 2001, pp. 4431
The contribution of the itinerant states to the magnetocrystalline anisotro
py (MA) energy of YCo5 and isostructural compounds has been calculated usin
g a fully relativistic optimized LCAO band-structure scheme within the fram
ework of density-functional theory in local spin density approximation (LSD
A), and its dependence on lattice geometry and Fe substitution has been inv
estigated. Additionally taking into account orbital polarization, a correct
ion to LSDA accounting for Hund's second rule. enhances the calculated orbi
tal moments. orbital moment anisotropies and MA energies, and leads to good
agreement with available experimental data for YCo5. The MA energies are f
ound to be strongly affected by changes of the lattice geometry (cin ratio
and volume) resulting from (i) uniaxial strain in YCo5 and (ii) the lanthan
ide contraction along the RCo5 (R = Y, La, Pr, Nd, Sm, Gd) series. because
of the sensitivity of the MA energy to changes of the band structure. We ob
tain a large variation of the MA energy of RCo5 along the R series which is
shown to be predominantly a lattice geometry effect. It is in contrast to
the commonly assumed independence of the transition-metal sublattice MA on
the R constituent. The calculated band-filling dependence of the MA energie
s of ordered Y(Co1 - xFex)(5) compounds (x=0.0.4.0.6,1.0) qualitatively exp
lains the experimentally observed concentration dependence of the MA energy
in Y(Co1 - xFex)(5) pseudobinaries at low Fe concentrations.