Domain state and exchange coupling in MnPt with Co clusters.
This Letter reports on the exchange coupling between nanometric Co clusters and disordered MnPt thin films. It is found that, under field-cooling, the MnPt develops a bulk magnetization M_{AF}. The correlation between M_{AF} and the exchange bias H_{b} is studied using a different field-cooling procedure. From this, using a mean-field approach, it is shown that the effective field acting on the interface magnetization responsible for H_{b} is proportional to M_{AF}. This results is strong evidence in favor of the domain state model for exchange bias, in which H_{b} is correlated with the bulk magnetic state of the antiferromagnet, and not only restricted to its interface configuration.
Morel
Robert
R
CEA Grenoble, DRFMC/SP2M, 17 rue des Martyrs, 38054 Grenoble cedex 9, France. robert.morel@cea.fr
Portemont
Céline
C
Brenac
Ariel
A
Notin
Lucien
L