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arXiv · 2004.06028

Impact of the surface phase transition on magnon and phonon excitations in BiFeO3 nanoparticles

Ian Aupiais·Pierre Hemme·Marc Allen·Alexis Scida·Xiao Lu·Christian Ricolleau·Yann Gallais·Alain Sacuto·Stanislaus Wong·Rogério de Sousa·Maximilien Cazayous
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Abstract

We have performed Raman scattering measurements on BiFeO3 nanoparticles and studied both magnetic and lattice modes. We reveal strong anomalies between 140 K and 200 K in the frequency of magnon and E(LO1), E(TO1) and A1(LO1) phonon modes. These anomalies are related to a surface expansion and are enhanced for nanoparticle sizes approaching the spin cycloidal length. These observations point out the strong interplay between the surface, the lattice, and the magnetism for sizes of BiFeO3 nanoparticles close to the cycloid periodicity.

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Ian Aupiais, Pierre Hemme, Marc Allen, Alexis Scida, Xiao Lu, Christian Ricolleau, Yann Gallais, Alain Sacuto, Stanislaus Wong, Rogério de Sousa, Maximilien Cazayous. 2020-04-13. Impact of the surface phase transition on magnon and phonon excitations in BiFeO3 nanoparticles. https://doi.org/10.1063/5.0003853

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