Exchange bias model in ferromagnetic/antiferromagnetic bilayer with L1/sub 2/-type ordered antiferromagnet

The exchange bias of the ferromagnetic (FM) and antiferromagnetic (AFM) bilayer having L1/sub 2/-type ordered structure has been investigated within the framework of Heisenberg model. The triangle lattice of magnetic atoms in the AFM layer realizes the triangular spin structure due to geometrical spin frustrations. This noncollinear spin structure can bring about an exchange bias in the FM/AFM bilayer system. Under the influence of the exchange bias, the uncompensated spin element appears in the AFM layer, resulting in a shifted loop in magnetization curves, in accord with the measured loop by X-ray magnetic circular dichroism spectroscopy for an AFM layer.