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arXiv · 1306.5563

Melting of chiral order in terbium manganate (TbMnO3) observed with resonant x-ray Bragg diffraction

S W Lovesey·V Scagnoli·M Garganourakis·S M Koohpayeh·C Detlefs·U Staub
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Abstract

Resonant Bragg diffraction of soft, circularly polarized x-rays has been used to observe directly the temperature dependence of chiral-order melting in a motif of Mn ions in terbium manganate. The underlying mechanism uses the b-axis component of a cycloid, which vanishes outside the polar phase. Melting is witnessed by the first and second harmonics of a cycloid, and we explain why the observed temperature dependence is different in the two harmonics. Our direct observation of melting is supported by a solid foundation of evidence, derived from extensive studies of the azimuthal-angle dependence of intensities with both linear and circular polarization.

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S W Lovesey, V Scagnoli, M Garganourakis, S M Koohpayeh, C Detlefs, U Staub. 2013-06-28. Melting of chiral order in terbium manganate (TbMnO3) observed with resonant x-ray Bragg diffraction. https://doi.org/10.1088/0953-8984%2F25%2F36%2F362202

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