ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
Perpendicular magnetic alignment is vital for high density magneto-optical recording materials. Despite the tremendous theoretical/computional advances made during the last few decades, the determination of magnetocrystalline anistropy (MCA) from first principles still remains a great challenge for complex systems. We will describe our recently proposed torque method for the first principles determination of MCA. In the usual first principles methods, one calculates the band energies associated with two magnetization directions and substracts one from the other. Within this approach, one has the difficulty of getting rid of the random fluctuations arising from the two different Fermi surfaces due to different magnetization directions. We show that to accurately determine the spin-orbit induced uniaxial ansisotropy energy for surfaces/interfaces, calculation of the torque at a specific angle is sufficient and one avoids the complexities associated with two Fermi surfaces by employing the Feynman-Hellman theorem. In the k-space integrations, we used both linear and quadratic interpolation schemes and convergence is assured when these two schemes agree to the accuracy desired. Examples, including Fe and Co multilayer systems, will be presented to demonstrate the efficiency and precision of this method. Detailed comparisons with previously proposed state-tracing method by Wang et al. are also made and discussed. © 1996 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.362200
