Optical properties and magnetochromism in multiferroic BiFeO3

Publication Type:

Journal Article

Source:

Physical Review B - Condensed Matter and Materials Physics, Volume 79, Number 13 (2009)

Abstract:

In order to investigate spin-charge coupling in multiferroic oxides, we measured the optical properties of BiFeO3. Although the direct 300 K charge gap is observed at 2.67 eV, absorption onset actually occurs at much lower energy with Fe3+ 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 to map out the magnetic-field-temperature phase diagram which demonstrates optical evidence for spin spiral quenching above 20 T and suggests a spin domain reorientation near 10 T. © 2009 The American Physical Society.

Notes:

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