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arXiv · 1506.06491

Helical bunching and symmetry lowering inducing multiferroicity in Fe langasites

Laura Chaix·Rafik Ballou·Andres Cano·Sylvain Petit·Sophie De Brion·Jacques Ollivier·Louis-Pierre Regnault·Eric Ressouche·Evan Constable·Claire Colin·A. Zorko·Valerio Scagnoli·Joël Balay·Pascal Lejay·Virginie Simonet
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Abstract

The chiral Fe-based langasites represent model systems of triangle-based frustrated magnets with a strong potential for multiferroicity. We report neutron scattering measurements for the multichiral Ba3MFe3Si2O14 (M = Nb, Ta) langasites revealing new important features of the magnetic order of these systems: the bunching of the helical modulation along the c-axis and the in-plane distortion of the 120{\textdegree} Fe-spin arrangement. We discuss these subtle features in terms of the microscopic spin Hamiltonian, and provide the link to the magnetically-induced electric polarization observed in these systems. Thus, our findings put the multiferroicity of this attractive family of materials on solid ground.

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Laura Chaix, Rafik Ballou, Andres Cano, Sylvain Petit, Sophie De Brion, Jacques Ollivier, Louis-Pierre Regnault, Eric Ressouche, Evan Constable, Claire Colin, A. Zorko, Valerio Scagnoli, Joël Balay, Pascal Lejay, Virginie Simonet. 2015-06-22. Helical bunching and symmetry lowering inducing multiferroicity in Fe langasites. https://doi.org/10.1103/physrevb.93.214419

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