Magnon Excitation Spectrum in Ferromagnetic Quasicubic Manganites

Author

Schlottmann, P.

Author_Institution

Dept. of Phys., Florida State Univ., Tallahassee, FL, USA

Volume

46

Issue

6

fYear

2010

fDate

6/1/2010 12:00:00 AM

Firstpage

1295

Lastpage

1298

Abstract

The magnon excitation spectrum of ferromagnetic quasicubic manganites is studied by using the linearized spin-wave approximation for the double-exchange and the superexchange interactions. Two situations are distinguished: 1) a rigid coupling of the t_2g and e_g spins via a large Hund´s rule coupling and 2) a softened coupling between these spins (e.g., due to coupling of the e_g electrons to Jahn-Teller modes). Case 2) leads to a softening of the magnon dispersion (compared to the Heisenberg model) close to the zone boundary.

Keywords

Heisenberg model; Jahn-Teller effect; calcium compounds; ferromagnetic materials; lanthanum compounds; magnons; spin waves; superexchange interactions; Heisenberg model; Hund´s rule coupling; Jahn-Teller modes; La_1-xCa_xMnO₃; double-exchange; ferromagnetic quasicubic manganites; linearized spin-wave approximation; magnon excitation spectrum; superexchange interactions; Antiferromagnetic materials; Electrons; Helium; Insulation; Lattices; Linear approximation; Magnetic separation; Nearest neighbor searches; Physics; Softening; Double exchange; magnetic excitations; manganites; superexchange;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/TMAG.2010.2044371

Filename

5467563