Lawrence Berkeley National Laboratory

Models of exchange bias put different emphasis on certain features in the magnetic microstructure of the interface between the ferromagnet and the antiferromagnet. Some stress the role of a) planar or b) vertical domain walls whereas others emphasize the role of c) uncompensated interface spins. Using X-ray Photoemission Electron Microscopy and X-ray Spectroscopy using X-ray Magnetic Dichroism, we will show that all three play a role, although planar walls only appear in soft antiferromagnets like single crystalline NiO [1]. Lateral walls enhance bias as will be shown in a statistical analysis of the domain-size-dependent bias field in LaFeO3 [2]. This work was supported by the U.S. Department of Energy under Contract No. DE-AC03-76SF00098 at Lawrence Berkeley National Laboratory.