Ab initio density functional calculations of ferromagnetism in low-dimensional nanostructures: From nanowires to nanorods

Author(s)
Martin Zeleny, Mojmir Sob, Juergen Hafner
Abstract

We present ab initio spin-density functional calculations of the electronic and magnetic properties of Fe and Ni nanostructures with a geometry varying between a straight linear wire and a three-dimensional nanorod. With decreasing tension along the axis of the nanostructure we find a series of transitions first from dimerized to periodic and zigzag wires, then to a planar triangular stripe, and further to a nanorod consisting of a periodic stacking of triangular antiprims. In all nanostructures atoms are in a high-moment state, with magnetic moments of about 3.1muB for Fe and about 1muB for Ni. A transition to a low-spin or nonmagnetic state is initiated at a fixed critical value of the interatomic distance, independent of dimension and coordination number. The analysis of the electronic structure shows that already for the one-dimensional nanostructures the ratio between exchange splitting and magnetic moment is close to the universal value I=Delta/ Mtilde 1eV/muB established for bulk itinerant magnets.

Organisation(s)
Computational Materials Physics
External organisation(s)
Masaryk University
Journal
Physical Review B
Volume
79
No. of pages
10
ISSN
1098-0121
DOI
https://doi.org/10.1103/PhysRevB.79.134421
Publication date
2009
Peer reviewed
Yes
Austrian Fields of Science 2012
103018 Materials physics
Portal url
https://ucrisportal.univie.ac.at/en/publications/2968dd38-2672-49ed-835a-26c1be2460cb