Interlayer exchange coupling in Nb/Fe multilayers

Abstract

The (110) oriented Nb-Fe multilayers (MLs) with constant Fe and variable Nb sublayer thicknesses were prepared at room temperature using UHV magnetron sputtering. The artificial periodicity was revealed by intense satellite peaks in the low- and high-angle X-ray diffraction patterns. Magnetic hysteresis loop measurements at 5 K revealed antiferromagnetic (AF) exchange coupling of the Fe sublayers for Nb spacer thickness of about 3 monolayers. The corresponding AF coupling energy is equal to about -1.36 mJ/m2. The Nb spacer thickness corresponding to the position of the AF peak is in good agreement with ab-initio calculations within localized spin density approximations of exchange-correlation potential.