Regensburg 2004 – wissenschaftliches Programm

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TT: Tiefe Temperaturen

TT 14: FV-internes Symposium ”Orbital Physics”

TT 14.7: Vortrag

Dienstag, 9. März 2004, 16:20–16:35, H18

Bond centered vs. site-centered charge ordering and ferroelectricity in oxides. — •Dmitry Efremov¹, Jeroen van den Brink², and Daniel Khomskii³ — ¹Technische Universität Dresden, Institut für Theoretische Physik, 01062 Dresden — ²Institut-Lorentz for Theoretical Physics, Universiteit Leiden, 2300 RA Leiden, The Netherlands — ³Universität zu Köln, 50937 Köln

Many transition metal oxides show charge ordering, which up to now was always treated as alternation of valency of transition metal ions. We show that besides this site-centered charge ordering there may exist another type of charge and orbital ordering, namely bond-centered ordering. We demonstrate that such type of ordering should exist in manganites close to half-filling. Moreover we show that these two types of ordering may coexist making the system ferroelectric.

16:35 Pause