Hyper-domains in exchange bias micro-stripe pattern
Abstract
A combination of experimental techniques, e.g. vector-MOKE magnetometry, Kerr microscopy and polarized neutron reflectometry, was applied to study the field induced evolution of the magnetization distribution over a periodic pattern of alternating exchange bias stripes. The lateral structure is imprinted into a continuous ferromagnetic/antiferromagnetic exchange-bias bi-layer via laterally selective exposure to He-ion irradiation in an applied field. This creates an alternating frozen-in interfacial exchange bias field competing with the external field in the course of the re-magnetization. It was found that in a magnetic field applied at an angle with respect to the exchange bias axis parallel to the stripes the re-magnetization process proceeds via a variety of different stages. They include coherent rotation of magnetization towards the exchange bias axis, precipitation of small random (ripple) domains, formation of a stripe-like alternation of the magnetization, and development of a state in which the magnetization forms large hyper-domains comprising a number of stripes. Each of those magnetic states is quantitatively characterized via the comprehensive analysis of data on specular and off-specular polarized neutron reflectivity. The results are discussed within a phenomenological model containing a few parameters which can readily be controlled by designing systems with a desired configuration of magnetic moments of micro- and nano-elements.
Cite
@article{arxiv.0803.2144,
title = {Hyper-domains in exchange bias micro-stripe pattern},
author = {K. Theis-Broehl and A. Westphalen and H. Zabel and U. Ruecker and J. McCord and V. Hoeink and J. Schmalhorst and G. Reiss and T. Weis and D. Engel and A. Ehresmann and B. P. Toperverg},
journal= {arXiv preprint arXiv:0803.2144},
year = {2009}
}
Comments
11 pages, 7 figures