We have studied the influence of the interface roughness on the giant magnetoresistance (GMR) of polycrystalline Fe/Cr superlattices, grown by molecular beam epitaxy on polycrystalline substrates. The interface quality was changed systematically by varying the growth temperature between 0 and 400 °C and by the use of a Cr seed layer. X-ray-diffraction spectra, combined with resistivity data, show that a moderate step density at the interfaces can enhance the GMR, whereas interdiffusion and important interface roughness strongly suppress the GMR.

• Received 20 June 1994

DOI:https://doi.org/10.1103/PhysRevB.50.9957