Two-phonon coupling to the antiferromagnetic phase transition in multiferroic BiFeO3

Journal Article

Ramirez, M.O, M Krishnamurthi, S Denev, A Kumar, S.-Y Yang, Y.-H Chu, E Saiz, J Seidel, A.P Pyatakov, A Bush, D Viehland, J Orenstein, Ramamoorthy Ramesh, V Gopalan

10.1063/1.2829681

A prominent band centered at ∼1000-1300 cm-1 and associated with resonant enhancement of two-phonon Raman scattering is reported in multiferroic BiFe O3 thin films and single crystals. A strong anomaly in this band occurs at the antiferromagnetic Neel temperature, TN ∼375 °C. This band is composed of three peaks, assigned to 2 A4, 2 E8, and 2 E9 Raman modes. While all three peaks were found to be sensitive to the antiferromagnetic phase transition, the 2 E8 mode, in particular, nearly disappears at TN on heating, indicating a strong spin-two-phonon coupling in BiFe O3. © 2008 American Institute of Physics.

Applied Physics Letters

92

2008

00036951

cited By 94

Ramesh Lab