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Anharmonic Phonons and Magnons in BiFeO3
- Source :
- Phys. Rev. B 85, 064405 (2012)
- Publication Year :
- 2011
-
Abstract
- The phonon density of states (DOS) and magnetic excitation spectrum of polycrystalline BiFeO$_3$ were measured for temperatures $200 \leq T \leq 750\,$K, using inelastic neutron scattering (INS). Our results indicate that the magnetic spectrum of BiFeO$_3$ closely resembles that of similar Fe perovskites, such as LaFeO$_3$, despite the cycloid modulation in BiFeO$_3$. We do not find any evidence for a spin gap. A strong $T$-dependence of the phonon DOS was found, with a marked broadening of the whole spectrum, providing evidence of strong anharmonicity. This anharmonicity is corroborated by large-amplitude motions of Bi and O ions observed with neutron diffraction. These results highlight the importance of spin-phonon coupling in this material.
Details
- Database :
- arXiv
- Journal :
- Phys. Rev. B 85, 064405 (2012)
- Publication Type :
- Report
- Accession number :
- edsarx.1110.3873
- Document Type :
- Working Paper
- Full Text :
- https://doi.org/10.1103/PhysRevB.85.064405