Dresden 2009 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 3: Magnetic Half Metals and Oxides
MA 3.7: Vortrag
Montag, 23. März 2009, 12:30–12:45, HSZ 401
Magnetism without magnetic impurities in oxides ZrO2 and TiO2 — •Frantisek Maca1, Josef Kudrnovsky1, Vaclav Drchal2, and Georges Bouzerar2,3 — 1Institute of Physics ASCR, Praha, Czech Republic — 2Institut Néel, CNRS, Grenoble, France — 3Institut Laue Langevin, Grenoble France
We perform a theoretical study of the magnetism induced in transition metal dioxides ZrO2 and TiO2 by substitution of the cation by a vacancy or an impurity from the groups 1A or 2A of the periodic table, where the impurity is either K or Ca.
In the present study both supercell and embedded cluster methods are used. It is demonstrated that the vacancy and the K-impurity leads to a robust induced magnetic moment on the surrounding O-atoms for both the cubic ZrO2 and rutile TiO2 host crystals. The presence of an impurity band close to the top of the valence band is a precursor for the appearance of magnetism in dioxides.
[1] F. Maca, J. Kudrnovsky, V. Drchal, and G. Bouzerar, Appl. Phys. Lett. 92, 212503 (2008).