MBE growth and structural and magnetic studies of high-quality single-crystal Co/Cr(001) superlattices

Abstract

High-quality Co/Cr(001) superlattices have been grown by the MBE method. At growth temperatures 300–350 °C we get sharp interfaces with a total roughness of about 7 Å. The Co layers exhibit a precursive structural change in direction to the metastable bcc phase as the Co layer thickness t Co decreases. Ferromagnetic, antiferromagnetic and biquadratic interlayer coupling of Co spins with spin orientations perpendicular to the film plane are observed below a critical t Co of about 15 Å. The strong t Cr-dependence of the interlayer coupling indicates the existence of short- and long-period oscillations similar to those of Fe/Cr(001).