Multiscale studies of complex magnetism of nanostructures based on first principles

Abstract

We present a first principles formulation that allows the derivation of parameters of a classical spin-model. In particular, relativistic effects are included, inducing tensorial exchange interactions and on-site anisotropy. Three applications of the method are shown: (i) by using a mean field treatment of the spin-model we calculate the temperature dependence of the magnetic anisotropy energy of a Co₃Cu(001) film; (ii) in terms of Monte Carlo simulations for an Fe₂/W(110) film we demonstrate the sensitivity of the magnetic ground state to the layer relaxations; and (iii) we also investigate the magnetic ground state of an equilateral Cr trimer on top of a Au(111) surface. These examples clearly highlight the importance of the anisotropic exchange couplings and of the Dzyaloshinsky-Moriya interactions in studying and understanding the magnetism of nanostructures.

Keywords:

• magnetic anisotropy
• exchange interactions
• magnetic nanostructures
• magnetic nanoparticles
• magnetic properties
• thin films

Acknowledgements

Financial support was provided by the Hungarian National Scientific Research Foundation (contract no. OTKA T068312, F68726 and NF061726).