| Autor: |
Ulbrich, H., Krüger, F., Nugroho, A. A., Lamago, D., Sidis, Y., Braden, M. |
| Rok vydání: |
2011 |
| Předmět: |
|
| Zdroj: |
Phys. Rev. B 84, 094453 (2011) |
| Druh dokumentu: |
Working Paper |
| DOI: |
10.1103/PhysRevB.84.094453 |
| Popis: |
Inelastic neutron scattering experiments have been performed on single crystals of Nd$_{1-x}$Sr$_{x}$MnO$_{3}$ with x$\approx$0.5. Colossal magnetoresistance (CMR) in the manganites arises from the interplay between a ferromagnetic metallic and antiferromagnetic charge and orbital ordered insulating state. Therefore, it appears important to compare these phases concerning their underlying magnetic interaction parameters. Our investigations of the spin-wave disperion in the AFM ordered state of Nd$_{0.5}$Sr$_{0.5}$MnO$_{3}$ exhibits a strongly anisotropic stiffness. The sign of the anisotropy is characteristic for the site-centered model for charge and orbital ordering in half-doped manganites. Within this model, linear spin-wave theory yields a perfect description of the experimental dispersion. Furthermore, magnetic excitations in the ferromagnetic metallic state of Nd$_{1-x}$Sr$_{x}$MnO$_{3}$ with x=0.49 and x=0.50 exhibit nearly the same magnon dispersion which can be described with a Heisenberg model including nearest-neighbor interactions. |
| Databáze: |
arXiv |
| Externí odkaz: |
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