In many magnetic materials it is possible to change the size of the magnetic moments, typically reduce, by application of pressure. Such transition is usually abrupt and sometimes is accompanied transtion to a metallic state. Using the LDA+DMFT computational scheme we were able to obtain such a behavior in MnO and Fe2O3 in agreement with experimental observations. We have identified the microscopic mechanisms responsible for these transitions and explained the observed changes in the density of the materials accompanying the transition.
Effect of pressure on the electronic spectrum Mn in MnO. Top: the high-pressure metallic phase, bottom: low-pressure insulator (with a large gap of several eV).
Collapse of magnetic moment drives the Mott transition in MnO, J. Kuneš, A. V. Lukoyanov, V. I. Anisimov, R. T. Scalettar, W. E. Pickett, Nature Materials 7 (2008) 198-202.
Pressure-Driven Metal-Insulator Transition in Hematite from Dynamical Mean-Field Theory, J. Kuneš, Dm. M. Korotin, M. A. Korotin, V. I. Anisimov, and P. Werner, Phys. Rev. Lett. 102 (2009) 146402.
Z izolátoru skokem vodič,
Lidové noviny, 7.2.2008
How Crystal Becomes a Conductor, (www.chemeurope.com) 7.2.2008
Study shows how crystals become conductors, (www.dailyindia.com) 6.2.2008
How crystal becomes a conductor, (www.physorg.com) 5.2.2008
Turning Crystals Into Conductors, (www.redorbit.com) 6.2.2008
Vom Isolator zum Metall, (www.pro-physik.de) 6.2.2008
Warum
Manganoxid bei hohen Drücken plötzlich zum Metall wird,
(www.pressrelations.de) 5.2.2008
Copyright © 2008-2014, Fyzikální ústav AV ČR, v. v. i.
