Noncollinear magnetism in transition metal nanostructures: Exchange interaction and local environment effects in free and deposited clusters Article uri icon

abstract

  • A self-consistent tight-binding theory of noncollinear magnetism in transition metal nanostructures is presented and applied to free and deposited clusters. The electronic structure is calculated by using a realistic rotational invariant tight-binding Hamiltonian and a real-space recursive expansion of the local Green%27s functions. For free clusters with sizes N≤13, results are given for the ground-state local magnetic moments, magnetic order, and average magnetic moments as a function of the Coulomb exchange integral J and d-band filling. A variety of qualitatively different noncollinear spin arrangement solutions are obtained, which reveals the complex magnetic landscape in transition metal nanostructures. The onset of noncollinear magnetism is discussed by analyzing the stability of the various magnetic solutions. Structural effects are studied by considering representative compact and open geometries. The calculations are compared with available density-functional results. Substrate effects on the noncollinearity of the moments are discussed by considering small Fe clusters deposited on Pt(111). Extensions and limitations of our work are also pointed out. © 2011 American Physical Society.
  • A self-consistent tight-binding theory of noncollinear magnetism in transition metal nanostructures is presented and applied to free and deposited clusters. The electronic structure is calculated by using a realistic rotational invariant tight-binding Hamiltonian and a real-space recursive expansion of the local Green's functions. For free clusters with sizes N≤13, results are given for the ground-state local magnetic moments, magnetic order, and average magnetic moments as a function of the Coulomb exchange integral J and d-band filling. A variety of qualitatively different noncollinear spin arrangement solutions are obtained, which reveals the complex magnetic landscape in transition metal nanostructures. The onset of noncollinear magnetism is discussed by analyzing the stability of the various magnetic solutions. Structural effects are studied by considering representative compact and open geometries. The calculations are compared with available density-functional results. Substrate effects on the noncollinearity of the moments are discussed by considering small Fe clusters deposited on Pt(111). Extensions and limitations of our work are also pointed out. © 2011 American Physical Society.

publication date

  • 2011-01-01