Morgan, Dane and Wang, Billie and Ceder, Gerbrand and van de Walle, Axel (2003) First-principles study of magnetism in spinel MnO2. Physical Review B, 67 (13). Art. No. 134404. ISSN 1098-0121. http://resolver.caltech.edu/CaltechAUTHORS:MORprb03
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First-principles electronic structure methods have been used to calculate the ground state, transition temperature, and thermodynamic properties of magnetic excitations in spinel MnO2. The magnetic interactions are mapped onto a Heisenberg model whose exchange interactions are fitted to results of first-principles calculations of different spin configurations. The thermodynamics are calculated using Monte Carlo methods. The Heisenberg model gives an extremely accurate representation of the true first-principles magnetic energies. We find a critical temperature and Weiss constant significantly larger than experimental results and believe the error to come from the local spin density approximation. We predict a new magnetic ground state different from that proposed previously, but consistent with experimental data.
|Additional Information:||©2003 The American Physical Society. Received: 3 September 2002; published: 3 April 2003. We would like to thank the Center for Materials Science and Engineering at MIT for their generous funding of this work. The authors acknowledge the support of the National Science Foundation (MRSEC Program) under Contract No. DMR 98-08941. Computing resources from NPACI, the National Partnership for Advanced Computing Infrastructure (NSF), are also gratefully acknowledged. We would also like to acknowledge valuable conversations with D.P. Landau, U. Amador, E. Arroyo, D. Carlier, A. Zunger, Clare Gray, and J. Greedan. We are particularly grateful to J. Greedan for generously providing us with the magnetic neutron diffraction data.|
|Subject Keywords:||manganese compounds; ab initio calculations; Heisenberg model; band model of magnetism; ground states; Monte Carlo methods; critical points; density functional theory; exchange interactions (electron); magnetic transition temperature; thermodynamic properties|
|Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited By:||Lindsay Cleary|
|Deposited On:||30 Oct 2006|
|Last Modified:||26 Dec 2012 09:14|
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