Optical properties and magnetochromism in multiferroicBiFeO3

X. S. Xu, T. V. Brinzari, S. Lee, Y. H. Chu, L. W. Martin, A. Kumar, S. McGill, R. C. Rai, R. Ramesh, V. Gopalan, S. W. Cheong, J. L. Musfeldt
2009 Physical Review B  
In order to investigate spin-charge coupling in multiferroic oxides, we measured the optical properties of BiFeO 3 . Although the direct 300 K charge gap is observed at 2.67 eV, absorption onset actually occurs at much lower energy with Fe 3+ excitations at 1.41 and 1.90 eV. Temperature and magnetic-field-induced spectral changes reveal complex interactions between on-site crystal-field and magnetic excitations in the form of magnon sidebands. We employ the sensitivity of these magnon sidebands
more » ... se magnon sidebands to map out the magnetic-fieldtemperature phase diagram which demonstrates optical evidence for spin spiral quenching above 20 T and suggests a spin domain reorientation near 10 T.
doi:10.1103/physrevb.79.134425 fatcat:lonvxjfngvhtjizbb5xet7m5lu