MBE GROWTH AND STRUCTURAL AND MAGNETIC STUDIES OF HIGH-QUALITY SINGLE-CRYSTAL CO CR(001) SUPERLATTICES/

High-quality Co/Cr(001) superlattices have been grown by the MBE metho d. At growth temperatures 300-350-degrees-C we get sharp interfaces wi th a total roughness of about 7 angstrom. The Co layers exhibit a prec ursive structural change in direction to the metastable bcc phase as t he Co layer thickness t(Co) decreases. Ferromagnetic, antiferromagneti c and biquadratic interlayer coupling of Co spins with spin orientatio ns perpendicular to the film plane are observed below a critical t(Co) of about 15 angstrom. The strong t(Cr)-dependence of the interlayer c oupling indicates the existence of short- and long-period oscillations similar to those of Fe/Cr(001).