We present results of anisotropy and exchange-coupling studies of asymmetric Co/Cr/Fe trilayers and superlattices grown by molecular beam epitaxy on Cr͑001͒/Mg͑001͒ buffers and substrates. The magnetic properties have been investigated using both the longitudinal magneto-optical Kerr effect and ferromagnetic resonance. The hysteresis data obtained from the trilayer system were fit to a theoretical model which contains both bilinear and biquadratic coupling. The effective in-plane anisotropy was found to be of fourfold symmetry with the same easy-axis orientation for both the Fe and Co layers. An analysis of the easy-axis hysteresis loops indicates long-period oscillatory coupling and also suggests a short periodic coupling. We show that weakly antiferromagnetically coupled asymmetric films might serve as potential candidates for improved spin-valve systems.

We present first results of anisotropy and exchange coupling studies of a system with two different magnetic layers (Fe and Co) separated by a nonmagnetic Cr spacer. For the magnetic measurements we used the longitudinal magneto-optical Kerr effect and ferromagnetic resonance. The hysteresis data obtained from the trilayer were fit to a theoretical model which contains both bilinear and biquadratic coupling. The in-plane anisotropy was found to be four-fold with the same easy-axis orientation for both the Fe and the Co layers. An analysis of the easy-axishysteresis loops indicates long period oscillatory coupling and also suggests a short period coupling.

Articles you may be interested inCombination of ultimate magnetization and ultrahigh uniaxial anisotropy in CoFe exchange-coupled multilayers J. Appl. Phys. 97, 10F910 (2005); 10.1063/1.1855171 Micromagnetic modeling of magnetization reversal of Fe/Cr/Co exchange coupled multilayers (abstract)