Giant magnetoresistance in Fe Cr superlattices with and without bulk scattering

Giant magnetoresistance (GMR) observed in magnetic multilayers is due to sp in-dependent electron scattering at interfaces and bulk defects. In order t o separate these two possible contributions we studied Fe/Cr superlattices with and without bulk defects (respectively polycrystalline and epitaxial s amples). The interface roughness was quantitatively analysed using X-ray di ffraction and conversion electron Mossbauer spectroscopy. The magnitude of the GMR effect depends on both the vertical roughness amplitude eta and the lateral correlation length xi(x) and increases with increasing eta/xi(x). (C) 1999 Elsevier Science B.V. All rights reserved.