Identifying the Magnetoelectric Modes of Multiferroic BiFeO3

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

DOI:https://doi.org/10.1103/PhysRevB.86.220402· OSTI ID:1059718

Fishman, Randy Scott ^[1]; Furukawa, N. ^[2]; Haraldsen, Jason T. ^[3]; Matsuda, Masaaki ^[1]; Miyahara, Shinya ^[4]

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1. ORNL
2. Aoyama Gakuin University, Kanagawa, Japan
3. Los Alamos National Laboratory (LANL)
4. Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea

We have identified three of the four magnetoelectric modes of multiferroic BiFeO3 measured using THz spectroscopy. Excellent agreement with the observed peaks is obtained by including the effects of easy-axis anisotropy along the direction of the electric polarization. By distorting the cycloidal spin state, anisotropy splits the 1 mode into peaks at 20 and 21.5 cm 1 and activates the lower 2 mode at 27 cm 1 (T = 200 K). An electromagnon is identified with the upper 1 mode at 21.5 cm 1. Our results also explain recent Raman and inelastic neutron-scattering measurements.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 1059718
• Journal Information: Physical Review B, Vol. 86, Issue 22; ISSN 1098--0121
• Country of Publication: United States
• Language: English