Anharmonic Phonons and Magnons in BiFeO3

Olivier Delaire; Matthew B. Stone; Jie Ma; Ashfia Huq; Delphine Gout; Craig Brown; Kefeng Wang; Zhifeng Ren

doi:10.1103/PhysRevB.85.064405

Anharmonic Phonons and Magnons in BiFeO3

Materials Science 2012-02-27 v3 Other Condensed Matter Strongly Correlated Electrons

Authors: Olivier Delaire , Matthew B. Stone , Jie Ma , Ashfia Huq , Delphine Gout , Craig Brown , Kefeng Wang , Zhifeng Ren

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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.

Keywords

BiFeO3 phonon density of states magnon spectrum anharmonicity inelastic neutron scattering spin-phonon coupling

Cite

@article{arxiv.1110.3873,
  title  = {Anharmonic Phonons and Magnons in BiFeO3},
  author = {Olivier Delaire and Matthew B. Stone and Jie Ma and Ashfia Huq and Delphine Gout and Craig Brown and Kefeng Wang and Zhifeng Ren},
  journal= {arXiv preprint arXiv:1110.3873},
  year   = {2012}
}

Anharmonic Phonons and Magnons in BiFeO3

Abstract

Keywords

Cite

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