| AVS 59th Annual International Symposium and Exhibition | |
| Magnetic Interfaces and Nanostructures | Tuesday Sessions |
| Session MI+EN+BI-TuA |
| Session: | Fundamental Problems in Magnetism |
| Presenter: | A.K. Kabir, University of Central Florida |
| Authors: | A.K. Kabir, University of Central Florida V. Turkowski, University of Central Florida T.S. Rahman, University of Central Florida |
| Correspondent: | Click to Email |
We use our recently proposed combined density-functional-theory/dynamical-mean-field-theory (DFT + DMFT) approach for molecules and nanosystems [1] to study the magnetic properties of Fe clusters consisting of 15, 17 and 19 atoms. This method has several advantages compared with the widely-used DFT + U approach for systems with localized electron states, the most important of which is that it takes into account dynamical correlation effects. These effects are especially important in the case when the kinetic (hopping) and the local Coulomb repulsion energies have the same order of magnitude. In particular, we study the size-dependence of the magnetic properties of the clusters by using the nanoDMFT code developed in our group using the iterated-perturbation theory approximation in the impurity solver. We find that the DFT+DMFT approach yields much better agreement for the magnetization with experimental data as compared to DFT and DFT+U methods, both of which generally overestimate the magnetization.
Work supported in part by DOE Grant No. DOE-DE-FG02-07ER46354
1. V. Turkowski, A. Kabir, N. Nayyar and T.S. Rahman J. Phys.: Condens. Matter 22, 462202 (2010) and J. Chem. Phys. 136, 114108 (2012)