Intralayer exchange coupling in Co/Ru/Co trilayers

The dependence of the interlayer exchange coupling in Si(0 0 1)/Ta/Co/Ru/Co/Ta trilayer on the thickness of the top Co layer is investigated. A strong in-plane uniaxial anisotropy is created in the magnetic layers by the shape anisotropy of an obliquely sputtered Ta underlayer, as confirmed by magnetometry and Brillouin light scattering measurements. The evolution of the magnetic properties, such as the magnetization at remanence and the saturation fields of the hysteresis loops and the giant magnetoresistance, is discussed in terms of the bilinear and biquadratic exchange coupling coefficients.