Fe/MnAs bilayers: Magnetic anisotropy and the role of the interface

The iron layer FMR spectrum is highly temperature dependent between 280 K and 320 K as its parameters are strongly altered in the α/β phase coexistence regime of the MnAs layer, revealing a strong interlayer coupling in this T-region. Additionally, the XPS experiments demonstrate the existence of an Fe-MnAs intermixed interface. This result would explain the appearance of an additional uniaxial anisotropy in the plane of the Fe films, together with a strong reduction in its magnetocrystalline anisotropy and a negligible direct exchange coupling in the MnAs ferromagnetic state.