Exchange Coupling and Exchange Bias in FM/AFM Bilayers for a Fully Compensated AFM Interface
B. Skubic, J. Hellsvik, L. Nordström and O. Eriksson
Department of Physics and Materials Science, Uppsala University, Box 530, SE-75121, Uppsala, Sweden
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We address the interlayer coupling in a ferromagnet/antiferromagnet bilayer where the interface of the antiferromagnet is fully compensated. We discuss the role of different types of exchange interaction for the interlayer coupling and exchange bias. We propose two types of corrections to the ideal Heisenberg Hamiltonian which may explain exchange bias. The first is a correction for the angular dependence of the exchange interactions and the second a correction due to magnetostriction and interface imperfections. The first correction contributes to an anisotropy at the interface and favors either parallel or perpendicular coupling across the interface. The second correction contributes to the exchange bias. Our analysis is based on atomic spin dynamics simulations, and our results show that small corrections to the ideal Heisenberg Hamiltonian may have macroscopic consequences in systems with frustrated interatomic interactions.
DOI: 10.12693/APhysPolA.115.25
PACS numbers: 75.50.Lk, 75.40.Mg, 75.10.Nr