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Infrared phonon dynamics of multiferroic BiFeO3 single crystal

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 نشر من قبل Ricardo Lobo
 تاريخ النشر 2007
  مجال البحث فيزياء
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We discuss the first infrared reflectivity measurement on a BiFeO3 single crystal between 5 K and room temperature. The 9 predicted ab-plane E phonon modes are fully and unambiguously determined. The frequencies of the 4 A1 c-axis phonons are found. These results settle issues between theory and data on ceramics. Our findings show that the softening of the lowest frequency E mode is responsible for the temperature dependence of the dielectric constant, indicating that the ferroelectric transition in BiFeO3 is soft-mode driven.



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