First-principles theory of electronic structure and magnetism of Cr nano-islands on Pd(1 1 1)

Abstract

We report on the electronic structure, magnetic moments and exchange interactions of one- and two-dimensional Cr clusters on a Pd(1 1 1) substrate, using a real-space method based on density functional theory in the local spin density approximation. We find in general that for the investigated clusters, the magnetic moments are sizeable and almost entirely of spin-character. We demonstrate that the interactions in general are dominated by nearest-neighbor antiferromagnetic Heisenberg form, which implies that Cr on Pd(1 1 1) forms an ideal model system, in which clusters of almost any shape and size can be investigated from a Heisenberg Hamiltonian, using a nearest-neighbor exchange model. We have also found that complex magnetic structures can be realized for linear chains of Cr, due to a competition between exchange interaction and a weaker Dzyaloshinskii-Moriya interaction.

Magnetic ground state of supported monatomic Fe chains from first principles

“…The real-space linear muffintin orbital method in the atomic sphere approximation (RS-LMTO-ASA) extended to non-collinear magnetic systems has been succesfully used to obtain the magnetic configurations of supported nanoclusters [28,29,30]. Including the effects of spin-orbit coupling, this parameter-free method was applied to explore the complex magnetic ground state of Mn nanowires on Ag(111) and Au(111) [31], as well as of Cr nanoislands on Pd(111) [32]. Using the constrained local moment method employed with the multiple scattering Green's function technique [33,34] the existence of a canted magnetic state of a Co chain along a Pt(111) surface step edge [35] was demonstrated from first principles in good agreement with experiment [36].…”

Magnetic ground state of supported monatomic Fe chains from first principles

“…The real-space linear muffin-tin orbital method in the atomic sphere approximation (ASA) extended to non-collinear magnetic systems has been successfully used to obtain the magnetic configurations of supported nanoclusters [29][30][31]. Including the effects of spin-orbit coupling, this parameterfree method was applied to explore the complex magnetic ground state of Mn nanowires on Ag(111) and Au(111) [32], as well as of Cr nano-islands on Pd(111) [33]. Using the constrained local moment method employed with the multiple scattering Green's function technique [34,35] the existence of a canted magnetic state of a Co chain along a Pt(111) surface step edge [36] was demonstrated from first principles in good agreement with experiment [37].…”