Dresden 2003 – wissenschaftliches Programm
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SYCN: Computational nanoscience - from materials to biology
SYCN 102: Computational Nanoscience: From Materials to Biology (Poster, gemeinsam mit SYSE)
SYCN 102.2: Poster
Dienstag, 25. März 2003, 19:00–21:00, ZEU/160
Electronic structure and magnetic interactions in ideal and defective transition-metal oxides — •Diemo Ködderitzsch1, Wolfram Hergert1, Zdsilawa Szotek2, and Walter M. Temmerman2 — 1Fachbereich Physik, Martin-Luther-Universität Halle-Wittenberg,Friedemann-Bach-Platz 6 Halle, Germany 06099 — 2Daresbury Laboratory, Daresbury, Warrington WA4 4AD, United Kingdom
Transition-metal oxides (TMO) are potential candidates for application in the new field of spintronics. Density-functional-theory using the local-spin-density approximation (DFT-LSD) is not able to provide the correct electronic structure of these materials due to the strongly correlated nature of interactions in these substances. Self-interaction corrected (SIC) DFT-LSD improves strongly the description of TMO. We have studied the magnetic interactions in NiO and the NiO(001)-surface in the framework of SIC-LSD-DFT. We characterise the magnetic interactions by extracted exchange-interaction constants of a Heisenberg-Hamiltonian. We have been able to describe the modification of the exchange-interaction constants when going from bulk to the surface. Further we have investigated in detail the influence of cation vacancies in MnO and NiO. We found vacancy induced half-metallic behaviour in both substances. In particular, for NiO we found a vanishing macroscopic magnetisation (“half-metallic antiferromagnet”) which might have technological importance.