Giant perpendicular magnetic anisotropy energies in CoPt thin films: Impact of reduced dimensionality and imperfections

Abstract

The impact of reduced dimensionality on the magnetic properties of the tetragonal L1${}_0$ CoPt alloy is investigated from ab-initio considering several kinds of surface defects. By exploring the dependence of the magnetocrystalline anisotropy energy (MAE) on the thickness of CoPt thin films, we demonstrate the crucial role of the chemical nature of the surface. For instance, Pt-terminated thin films exhibit huge MAEs which can be 1000% larger than those of Co-terminated films. Besides the perfect thin films, we scrutinize the effect of defective surfaces such as stacking faults or anti-sites on the surface layers. Both types of defects reduce considerably the MAE with respect to the one obtained for Pt-terminated thin films. A detailed analysis of the electronic structure of the thin films is provided with a careful comparison to the CoPt bulk case. The behavior of the MAEs is then related to the location of the different virtual bound states utilising second order perturbation theory.

arXiv comment10 pages, 7 figures, accepted in Journal of Physics: Condensed Matter

References in corpus (5)

• Coulomb Correlations and Magnetic Anisotropy in ordered $L{1}_0$ CoPt and FePt alloys
• Surface energies of stoichiometric FePt and CoPt alloys and their implications for nanoparticle morphologies
• Magnetization reversal of giant perpendicular magnetic anisotropy at the magnetic-phase transition in FeRh films on MgO
• Magnetism: the Driving Force of Order in CoPt. A First-Principles Study
• Comparative study of tight-binding and ab initio electronic structure calculations focused on magnetic anisotropy in ordered CoPt alloy

Cited by in corpus (2)

• Understanding all-optical spin switching: Comparison between experiment and theory
• Impact of single atomic defects and vacancies on the magnetic anisotropy energy of CoPt thin films