Imaging, controlling and harnessing non-collinear magnetism in perovskite oxides

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 films and present real-space images of the cycloidal structure, as well as its manipulation by an electric field In a second part I will discuss how magnetic spin texture can influence the Hall response in strongly correlated oxide thin films.