Dresden 2006 – wissenschaftliches Programm

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MA: Magnetismus

MA 20: Poster: Films(1-36) Transp(37-56) Ex.Bias(57-67) Spindyn(68-80) Micromag(81-95) Particle(96-109) Imag.+Surface(110-113) Spinelectr(114-122) Theory+Micromag(123-131) Spinstr+Aniso(132-142) MagMat(143-156) Meas(157,158) MolMag+Kondo(159-162) Postdead(163-)

MA 20.115: Poster

Dienstag, 28. März 2006, 15:15–19:15, P1

Magnetism and Jahn-Teller induced band splitting in CMR materials — •Martin Stier and Wolfgang Nolting — Institut für Physik, Humboldt-Universität zu Berlin, Newtonstraße 15, 12489 Berlin, Germany

A model analysis is presented for the class of the manganites. Starting point is a correlated Kondo lattice model, which is extended by a Jahn-Teller term. In view of the electronic and magnetic properties, it is solved approximatly but self-consistently by use of finite Hund coupling and quantum spins. Explicit results are given for the Curie temperature, the band splitting, the electrical resistance and the quasi particle density of states. The outcome for realistic parameters is compared with experimental data. The Jahn-Teller splitting normally weakens the Curie temperature but there can also be an increase under special circumstances.