Abstract
The exchange integrals of manganese ferrite (MnFe₂O₄) are calculated with the density functional theory method for both normal and inverse spinel structures. The functional is chosen to be a mixture of Becke exchange and Fock exchange with variable weight (w). The exchange integrals JAB (the exchange integral between the nearest neighbor A and B sites) and JBB (the exchange integral between nearest neighbor B sites) are calculated by substituting the total energies of different magnetic ground states into the Heisenberg model. The calculated value of JAB is in agreement with experimental values measured by neutron diffraction and nuclear magnetic resonance. Also, the parameters U (Coulomb repulsion energy) and Eg (band gap) are extracted from density of states plotted versus w. Our calculated band gap shows that MnFe₂O₄ is a complex insulator in contrast to previous local spin density approximation and generalized gradient approximation calculations which predicted it to be metallic.
Keywords
manganese ferrite, density functional theory method, MnFe₂O₄, exchange integrals, Becke exchange, Fock exchange, JAB, JBB, Heisenberg model, Coulomb repulsion energy, calculated band gap
Subject Categories
Density functionals, Spinel, Magnetic resonance
Disciplines
Electromagnetics and photonics
Publisher
American Institute of Physics
Publication Date
5-15-2003
Rights Information
Copyright 2003 American Institute of Physics.
Rights Holder
American Institute of Physics
Permanent URL
Recommended Citation
Zuo, X. and Vittoria, C., "Calculation of exchange integrals and electronic structure of manganese ferrite (MnFe₂O₄)" (2003). Electrical and Computer Engineering Faculty Publications. Paper 27. http://hdl.handle.net/2047/d20002197
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Notes
Originally published in Journal of Applied Physics 93, 8017 (2003). DOI:10.1063/1.1558200 (http://dx.doi.org/10.1063/1.1558200).