Scientifique

Dual Antiferromagnetic Coupling at La_0:67Sr_0:33MnO₃/ SrRuO₃ Interfaces  

A. Solignac, R. Guerrero, P. Gogol, T. Maroutian, F. Ott, L. Largeau, Ph. Lecoeur, and M. Pannetier-Lecoeur
Phys. Rev. Lett. 109 (2012) 027201.

We have studied the magnetic hysteresis cycle of La_0;67Sr_0.33MnO₃/SrRuO₃ antiferromagnetically coupled bilayers, by magnetometry and polarized neutron reflectometry. A positive exchange bias as well as an unusual asymmetry are observed on the magnetic reversal process of the La_0;67Sr_0.33MnO₃ layer. Through an extended Stoner-Wohlfarth model comprising the magnetic anisotropy of both layers, we give experimental evidence that this asymmetry originates from two different but well-defined antiferromagnetic coupling strengths at the interface between the two magnetic oxides. The possible origin of this dual coupling is discussed in view of our experimental results.

A. Menelle, dépêche du 02/01/2013