In magnetic perovskite oxides ABO3, first-neighbour antiferromagnetic super-exchange interactions usually dominate, but may coexist with other terms such as ferromagnetic double-exchange or Dzyaloshinskii-Moriya interactions at B-O-B and A-O-A bonds. This often produces non-collinear spin configurations leading to weak ferromagnetism or to spatially modulated spin structures. A prototypical non-collinear magnetic oxide is multiferroic BiFeO3 that shows a cycloidal order with a 64 nm period in the bulk. In this talk, I will show how epitaxial strain can be used to tailor the magnetic order of BiFeO3 thin films1,2 and present real-space images of the cycloidal structure, as well as its manipulation by an electric field3. In a second part I will discuss how magnetic spin texture can influence the Hall response in strongly correlated oxide thin films. 

1.          Sando, D. et al. Crafting the magnonic and spintronic response of BiFeO3 films by epitaxial strain. Nature Mater. 12, 641–6 (2013).

2.          Agbelele, A. et al. Strain and Magnetic Field Induced Spin-Structure Transitions in Multiferroic BiFeO3. Adv. Mater. 29, 1602327 (2017).

3.          Gross, I. et al. Real-space imaging of non-collinear antiferromagnetic order with a single spin magnetometer. Nature (2017) (in press).

manuel.bibes@cnrs-thales.fr

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