Dzyaloshinskii-Moriya driven helical-butterfly structure in Ba3NbFe3Si2O14

Valerio Scagnoli (1) , Winnie S. Huang (1) , Mario Garganourakis (1) , Raquel A. de Souza (1) , Urs Staub (1) , Virginie Simonet (2) , Pascal Lejay (3) , Rafik Ballou (2)

1 SLS-PSI - The Swiss Light Source (SLS)
2 NEEL - MagSup - Magnétisme et Supraconductivité
3 NEEL - C2MA - Croissance Cristalline et MicroAnalyse

We have used soft x-ray magnetic diffraction at the Fe3+ L2,3 edges to examine to what extent the Dzyaloshinsky-Moriya interaction in Ba3NbFe3Si2O14 influences its low-temperature magnetic structure. A modulated component of the moments along the c axis is present, adding to the previously proposed helical magnetic configuration of coplanar moments in the a,b plane. This leads to a "helical-butterfly" structure and suggests that both the multiaxial in-plane and the uniform out-of-plane Dzyaloshinsky-Moriya vectors are relevant. A nonzero orbital magnetic signal is also observed at the oxygen K edge, which reflects the surprisingly strong hybridization between iron 3d and oxygen 2p states, given the nominal spherical symmetry of the Fe3+ half-filled shell.

Domaines: Electrons fortement corrélés [cond-mat.str-el]

Valerio Scagnoli, Winnie S. Huang, Mario Garganourakis, Raquel A. de Souza, Urs Staub, et al.. Dzyaloshinskii-Moriya driven helical-butterfly structure in Ba3NbFe3Si2O14. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2013, 88, pp.104417. ⟨10.1103/PhysRevB.88.104417⟩. ⟨hal-00963848⟩