Anharmonic phonons and magnons in BiFeO3

Journal Article · Sun Jan 01 00:00:00 EST 2012 · Physical Review B

DOI:https://doi.org/10.1103/PhysRevB.85.064405· OSTI ID:1035536

Delaire, Olivier A ^[1]; Ma, Jie ^[1]; Stone, Matthew B ^[1]; Huq, Ashfia ^[1]; Gout, Delphine J ^[1]; Brown, Craig ^[2]; Wang, Kefeng ^[3]; Ren, Zhifeng ^[4]

---

1. ORNL
2. National Institute of Standards and Technology (NIST)
3. Nanjing National Laboratory of Microstructures, Nanjing University, Nanjing
4. Boston College, Chestnut Hill

The phonon density of states (DOS) and magnetic excitation spectrum of polycrystalline BiFeO3 were measured for temperatures 200 < T < 750K , 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. These results highlight the importance of spin-phonon coupling in this material.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 1035536
• Journal Information: Physical Review B, Vol. 85, Issue 6; ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
AMPLITUDES
EXCITATION
MAGNONS
MODULATION
NEUTRON DIFFRACTION
NEUTRONS
PEROVSKITES
PHONONS
SCATTERING
SPIN
multiferroic
phonon
magnon
neutron scattering