2007/10/10 by C. Vecchini L. C. Chapon, C. Chapon, P. J. Brown +10 · 1 citation
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Multiferroics and related materials #Solid-state spectroscopy and crystallography #cond-mat.mtrl-sci
paper · pdf · doi:10.48550/arxiv.0710.2065
arxiv created 2007/10/10 · openalex publication_date 2007/10/10 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Precise magnetic structures of RMn2O5, with R= Y, Ho, Bi in the commensurate/ferroelectric regime, have been determined by single-crystal neutron diffraction. For each system, the integrated intensities of a large number of independent magnetic Bragg reflections have been measured, allowing unconstrained least-squares refinement of the structures. The analysis confirms the previously reported magnetic configuration in the ab-plane, in particular the existence of zig-zag antiferromagnetic chains. For the Y and Ho compounds additional weak magnetic components parallel to the c-axis were detected which are modulated in phase quadrature with the a-b components. This component is extremely small in the BiMn2O5 sample, therefore supporting symmetric exchange as the principal mechanism inducing ferroelectricity. For HoMn2O5, a magnetic ordering of the Ho moments was observed, which is consistent with a super-exchange interaction through the oxygens. For all three compounds, the point symmetry in the magnetically ordered state is m2m, allowing the polar b-axis found experimentally.