Coercivity enhancement in exchange biased systems driven by interfacial magnetic frustration
We report the temperature and cooling field dependence of the coercivity of exchange biased MnF(2)/Fe bilayers. When the antiferromagnetic surface is in a state of maximum magnetic frustration and the net exchange bias is zero, we observe a strong enhancement of the coercivity, which is proportional to the exchange coupling between the layers. Hence, the coercivity can be tuned in a reproducible and repeatable fashion in the same sample. We propose that a frustrated interface provides local energy minima which effectively pin the propagating domain walls in the ferromagnet, leading to an enhanced coercivity.
Leighton
C
Physics Department 0319, University of California-San Diego, La Jolla, California 92093-0319, USA.
Nogues
J
Jonsson-Akerman
BJ
Schuller
IK