Abstract:
The magnetization dynamics of exchange-biased IrMn/CoFe bilayers have been investigated using broadband
and in-plane angle-dependent ferromagnetic resonance spectroscopy. The interface energy of the exchange bias
effect in these bilayers exceeds values previously reported for metallic antiferromagnets. A strong perpendicular
magnetic anisotropy and a small in-plane uniaxial anisotropy are also observed in these films. The magnetization
relaxation of the bilayers has a strong unidirectional contribution, which is in part caused by two-magnon
scattering. However, a detailed analysis of in-plane angle– and thickness-dependent linewidth data strongly
suggests the presence of a previously undescribed unidirectional relaxation mechanism.
