The magnetic structure of epitaxial Cr films on MgO

Abstract

In the last ten years a lot of attention has been paid to Fe/Cr multilayers and superlattices because of the giant magnetoresistance effect observed in such systems. More recently, for a better understanding of the observed oscillatory exchange coupling effects, few studies have focused on the intrinsic magnetic properties of Cr. It is from this viewpoint that the interest in thin Cr films has increased. Growth-induced effects, such as strains and defects can alter the magnetic phase diagram of Cr. In order to study these influences we prepared epitaxial Cr films on MgO by use of molecular beam epitaxy. The films were characterized using X-ray diffraction, Rutherford backscattering/channeling spectrometry and neutron diffraction. The presence of a small epitaxial strain causes the spins of the Cr to align preferentially along the growth direction. Up to a field of 4 T, no changes in spin orientation has been observed and neither could a magnetic Fe capping layer influence the spin structure.