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O. Delaire, M. B. Stone, J. Ma, A. Huq, D. Gout, Craig Brown, K. F. Wang, Z. F. Ren
Abstract
The phonon density of states (DOS) and magnetic excitation spectrum of polycrystalline BiFeO3 were measured for temperatures 200 less than or equal to}Τ less than or equal to} 750K, using inelastic neutron scattering (INS). Our results indicate that the magnetic spectrum BiFeO3 closely resembles that of similar Fe perovskites, such as LaFeO3, despite the cycloid modulation in BeFeO3. 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.
Delaire, O.
, Stone, M.
, Ma, J.
, Huq, A.
, Gout, D.
, Brown, C.
, Wang, K.
and Ren, Z.
(2012),
Anharmonic Phonons and Magnons in BiFeO<sub>3</sub>, Physical Review B, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=909957
(Accessed October 18, 2025)