Jahn-Teller effect and superexchange in half-doped manganites

• Published in: Physica Status Solidi (b) Vol. 236; no. 2; pp. 380 - 383
• Main Authors: Sikora, O., Oleś, A. M.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Berlin WILEY-VCH Verlag 01.03.2003; WILEY‐VCH Verlag; Wiley
• Subjects: 71.20.-b; 75.47.Gk; 75.50.Ee; Colossal magnetoresistance; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electron states; Exact sciences and technology; Exchange and superexchange interactions; Level splitting and interactions; Magnetic properties and materials; Magnetically ordered materials: other intrinsic properties; Magnetotransport phenomena, materials for magnetotransport; Physics; Spin-orbit coupling, Zeeman and Stark splitting, Jahn-Teller effect; Spin-orbit coupling, zeeman, stark, and strain splitting, jahn-teller effect; Phase diagrams; Inorganic compounds; Transition element compounds; Doping; Theoretical study; Microscopic model; Rare earth compounds; Jahn-Teller effect; Coulomb interaction; Perovskite; Mean-field theory; Strontium Manganites; Superexchange interactions; Charge transfer; Quaternary compounds; Lanthanum Manganites
• ISSN: 0370-1972; 1521-3951
• DOI: 10.1002/pssb.200301684

We investigate the stability of the charge exchange (CE) phase within a microscopic model which describes a single plane as in La0.5Sr1.5MnO4. The model includes Coulomb interactions (on‐site and intersite), the Jahn–Teller term and the superexchange interactions due to eg and t2g electrons. By investigating the phase diagram at T = 0 in mean‐field approximation we conclude that the superexchange interactions can stabilize the CE phase, but only if they are stronger than estimated from spectroscopy.