The suppression of NiO reduction in Fe/NiO systems by use of an ultrathin MgO buffer layer, investigated by photoemission and low energy electron diffraction

Ferromagnetic and antiferromagnetic multilayers are promising candidates for new magnetic sensors with spin-valve properties. At room temperature, thin Fe films with a thickness of about 5 monolayers (ML) were deposited on single crystalline NiO(0 0 1), grown epitaxially on bulk Ag(0 0 1). In order to suppress the occurrence of a distinct NiO reduction, a MgO film of different thicknesses (x = 2.5; 5.0 ML) was additionally deposited as a buffer layer. The different Fe/MgO/NiO/Ag(0 0 1) systems were investigated by means of photoemission and low energy electron diffraction. The main finding is, that the reduction of nickel oxide to nickel metal at the Fe/NiO interface can be nearly suppressed by the presence of few ML MgO between the Fe film and the NiO substrate. (C) 2002 Elsevier Science B.V. All rights reserved.