Two-Stage Magnetization Reversal in Exchange Biased Bilayers

C. Leighton; M. R. Fitzsimmons; P. Yashar; A. Hoffmann; J. Nogués; J. Dura; C. F. Majkrzak; Ivan K. Schuller

doi:10.1103/PhysRevLett.86.4394

Two-Stage Magnetization Reversal in Exchange Biased Bilayers

C. Leighton, M. R. Fitzsimmons, P. Yashar, A. Hoffmann, J. Nogués, J. Dura, C. F. Majkrzak, and Ivan K. Schuller

Phys. Rev. Lett. 86, 4394 – Published 7 May 2001

Abstract

${MnF}_{2} / Fe$ bilayers exhibit asymmetric magnetization reversal that occurs by coherent rotation on one side of the loop and by nucleation and propagation of domain walls on the other side of the loop. Here, we show by polarized neutron reflectometry, magnetization, and magnetotransport measurements that for samples with good crystalline “quality” the rotation is a two-stage process, due to coherent rotation to a stable state perpendicular to the cooling field direction. The result is remarkably asymmetrically shaped hysteresis loops.

Received 2 August 2000

DOI:https://doi.org/10.1103/PhysRevLett.86.4394

Authors & Affiliations

C. Leighton^1,*, M. R. Fitzsimmons², P. Yashar², A. Hoffmann², J. Nogués³, J. Dura⁴, C. F. Majkrzak⁴, and Ivan K. Schuller¹

¹Physics Department, University of California–San Diego, La Jolla, California 92093-0319
²Los Alamos National Laboratory, Los Alamos, New Mexico 87545
³Departament de Física, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
⁴National Institute of Standards and Technology, Gaithersburg, Maryland 20899