Rotation of the Pinning Direction in the Exchange Bias Training Effect in Polycrystalline $\mathrm{NiFe}/\mathrm{FeMn}$ Bilayers

Rotation of the Pinning Direction in the Exchange Bias Training Effect in Polycrystalline $NiFe / FeMn$ Bilayers

X. P. Qiu, D. Z. Yang, S. M. Zhou, R. Chantrell, K. O’Grady, U. Nowak, J. Du, X. J. Bai, and L. Sun

Phys. Rev. Lett. 101, 147207 – Published 3 October 2008

Abstract

For polycrystalline $NiFe / FeMn$ bilayers, we have observed and quantified the rotation of the pinning direction in the exchange bias training and recovery effects. During consecutive hysteresis loops, the rotation of the pinning direction strongly depends on the magnetization reversal mechanism of the ferromagnet layer. The interfacial uncompensated magnetic moment of antiferromagnetic grains may be irreversibly switched and rotated when the magnetization reversal process of the ferromagnet layer is accompanied by domain wall motion and domain rotation, respectively.

Received 22 January 2008

DOI:https://doi.org/10.1103/PhysRevLett.101.147207

Authors & Affiliations

X. P. Qiu, D. Z. Yang, and S. M. Zhou

Applied Surface Physics Laboratory (State Key Laboratory) and The State Key Lab for Advanced Photonic Materials Devices and Department of Physics, Fudan University, Shanghai 200433, China

R. Chantrell, K. O’Grady, and U. Nowak