Oscillations with a period of two Cr monolayers in the antiferromagnetic exchange coupling in a (001) Fe/Cr/Fe sandwich structure

Abstract

Oscillations with a period of two Cr monolayers were measured in the antiferromagnetic exchange coupling between Fe magnetizations separated by Cr. The coupling was measured on a sample consisting of a Au(20 \AA{})/Fe(50 \AA{})/Cr(0--18 \AA{} wedge) film deposited by molecular-beam epitaxy on a Fe[100] single-crystal ``whisker.'' The Cr and Fe grew monolayer by monolayer as monitored by reflection high-energy-electron diffraction. The coupling was determined from the magneto-optic Kerr effect. It was antiferromagnetic for 5--18 \AA{} Cr with four strong peaks and a maximum value of -0.60 mJ/${\mathrm{m}}^{2}$ for eight monolayers of Cr.