Non collinear spin textures such as skyrmions are currently under focus owing to their fundamental interest (associated with the influence of the topology of the spin configuration on electronic properties) and to their potential for applications in data storage.
Multiferroic BiFeO3 naturally possesses a non collinear spin order which is also controlable by an electric field. In BiFeO3, spins order along a 62-nm-period cycloid. In our study just out in Advanced Materials, we have shown that when BiFeO3 is grown in thin film form, both epitaxial strain and the application of an external magnetic field lengthen this period and may eventually destroy the cycloidal state. By combining several stimuli (strain, magnetic field, electric field), it thus appears possible to stabilize various non-collinear spin states, which bears a strong potential for spintonics and magnonics.
This work was done in collaboration with the Laboratoire MPQ (Université Paris-Diderot), the GPM (Université de Rouen), the SPMS lab (Ecole Centrale Paris), the ESRF, the ISIS facility and the Moscow Institute of Science and Technology.
Strain and Magnetic Field Induced Spin-Structure Transitions in Multiferroic BiFeO3
A. Agbelele et al, Adv. Mater. 1602327 (2017) ; DOI: 10.1002/adma.201602327
See also the News piece by Labex NanoSaclay (in French).