2008/02/21 by A. Antal, Ágnes Antal, B. Lazarovits +4 · 56 citations
Mathematics · Physics and Astronomy · #Antiferromagnetism #Cluster (spacecraft) #Condensed matter physics #Equilateral triangle #Geometry #Ground state #Isosceles triangle #Magnetic field #Magnetic properties of thin films #Magnetization #Mathematics #Nuclear magnetic resonance #Physics #Physics of Superconductivity and Magnetism #Quantum mechanics #Spin (aerodynamics) #Symmetry (geometry) #Theoretical and Computational Physics #Trimer #cond-mat.mtrl-sci #cond-mat.other
paper · pdf · doi:10.1103/physrevb.77.174429
published in Physical Review B 77(17) (American Physical Society) · 18 pages, 7 figures
arxiv created 2008/02/21 · openalex publication_date 2008/05/23 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We present calculations of the magnetic ground states of Cr trimers in different geometries on top of a Au(111) surface. By using a least squares fit method based on results obtained by means of a fully relativistic embedded-cluster Green's function method, first we determined the parameters of a classical spin vector model containing second- and fourth-order interactions. The developed method requires no a priori assumed symmetry constraints; therefore, it is applicable throughout for small nanoparticles of arbitrary geometry. The magnetic ground states were then found by solving the Landau-Lifshitz-Gilbert equations. In all cases considered, the configurational energy of the Cr trimers is dominated by large antiferromagnetic nearest neighbor interactions, while the biquadratic spin interactions provide the second largest contributions to the energy. We find that an equilateral Cr trimer exhibits a frustrated 120\ifmmode^∘\else\textdegree\fi N'eel type of ground state with a small out-of-plane component of the magnetization. Furthermore, we show that the Dzyaloshinsky-Moriya interactions determine the chirality of the magnetic ground state. In cases of a linear chain and an isosceles trimer, collinear antiferromagnetic ground states are obtained with the magnetization lying parallel to the surface.