Anharmonic phonons and magnons in BiFeO3

O. Delaire, M. B. Stone, J. Ma, A. Huq, D. Gout, C. Brown, K. F. Wang, and Z. F. Ren
Phys. Rev. B 85, 064405 – Published 13 February 2012

Abstract

The phonon density of states (DOS) and magnetic excitation spectrum of polycrystalline BiFeO3 were measured for temperatures 200T750K, using inelastic neutron scattering (INS). Our results indicate that the magnetic spectrum of BiFeO3 closely resembles that of similar Fe perovskites, such as LaFeO3, despite the cycloid modulation in BiFeO3. 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. A clear anomaly is seen in the T dependence of Bi-dominated modes across the Néel transition. These results highlight the importance of spin-phonon coupling in this material.

  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
1 More
  • Received 12 November 2011

DOI:https://doi.org/10.1103/PhysRevB.85.064405

©2012 American Physical Society

Authors & Affiliations

O. Delaire1, M. B. Stone1, J. Ma1, A. Huq1, D. Gout1, C. Brown2, K. F. Wang3, and Z. F. Ren3

  • 1Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
  • 2NIST Center for Neutron Research, Gaithersburg, Maryland 20899, USA
  • 3Department of Physics, Boston College, Boston, Massachusetts 02467, USA

Article Text (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand
Issue

Vol. 85, Iss. 6 — 1 February 2012

Reuse & Permissions
Access Options
CHORUS

Article Available via CHORUS

Download Accepted Manuscript
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review B

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×