title: Chirality switching and winding or unwinding of the antiferromagnetic NiO domain walls in Fe/NiO/Fe/CoO/Ag(001).
abstract: Fe/NiO/Fe/CoO/Ag(001) single crystalline films were grown epitaxially and investigated by x-ray magnetic circular dichroism and x-ray magnetic linear dichroism. The bottom Fe layer magnetization is pinned through exchange coupling to the CoO layer and the top Fe layer magnetization can be rotated by an in-plane external magnetic field. We find that the NiO spins wind up to form a domain wall due to the perpendicular NiO/Fe interfacial coupling as the top layer Fe magnetization rotates from 0° to 90°, but switch wall chirality and unwind the wall as the Fe magnetization rotates from 90° to 180°. This observation shows that Mauri's 180° domain wall does not exist in perpendicularly coupled ferromagnetic-antiferromagnetic systems in the strong coupling regime.
authors.affiliation: Department of Physics, University of California at Berkeley, Berkeley, California 94720, USA.
authors.forename: J
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of Physics, University of California at Berkeley, Berkeley, California 94720, USA.
authors.forename: A
authors.initials: A
authors.lastname: Tan
authors.affiliation: Department of Physics, University of California at Berkeley, Berkeley, California 94720, USA and Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China.
authors.forename: S
authors.initials: S
authors.lastname: Ma
authors.affiliation: Department of Physics, University of California at Berkeley, Berkeley, California 94720, USA.
authors.forename: R F
authors.initials: RF
authors.lastname: Yang
authors.affiliation: Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: E
authors.initials: E
authors.lastname: Arenholz
authors.affiliation: Korea Research Institute of Standards and Science, Yuseong, Daejeon 305-340, Korea.
authors.forename: C
authors.initials: C
authors.lastname: Hwang
authors.affiliation: Department of Physics, University of California at Berkeley, Berkeley, California 94720, USA.
authors.forename: Z Q
authors.initials: ZQ
authors.lastname: Qiu