Document Type
Article
Original Publication Date
2013
Journal/Book/Conference Title
The Journal of Chemical Physics
Volume
139
Issue
6
DOI of Original Publication
10.1063/1.4817335
Date of Submission
October 2015
Abstract
Electronic transport across a FeMg8 magnetic superatom and its dimer has been investigated using a density functional theory combined with Keldysh nonequilibrium Green's-function formalism. For a single cluster, our studies for the cluster supported in various orientations on a Au(100) surface show that the transport is sensitive to the contact geometry. Investigations covering the cases where the axes of Mg square antiprism are 45°, perpendicular, and parallel to the transport direction, show that the equilibrium conductance, transferred charge, and currentpolarizations can all change significantly with orientation. Our studies on the transport across a magnetic superatom dimer FeMg8–FeMg8 focus on the effect of electrode contact distance and the support. The calculated I-V curves show negative differential resistance behavior at larger electrode-cluster contact distances. Further, the equilibrium conductance in ferromagnetic state shows an unusually high spin polarization that is about 81.48% for specific contact distance, and a large magnetoresistance ratio exceeding 500% is also found. The results show that the superatom assemblies can provide unusual transport characteristics, and that the spinpolarization and magnetoresistance can be controlled via the contact geometry.
Rights
Zhu, L., Qian, M., & Khanna, S. N. Unusually large spin polarization and magnetoresistance in a FeMg8-FeMg8 superatomic dimer. The Journal of Chemical Physics, 139, 064306 (2013). © 2013 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License.
Is Part Of
VCU Physics Publications
Comments
Originally published at http://dx.doi.org/10.1063/1.4817335