Spin engineering: Direct determination of the Ruderman-Kittel-Kasuya-Yosida far-field range function in ruthenium
Oscillations in both ferromagnetic and antiferromagnetic indirect exchange coupling through Ru are directly measured. Ferromagnetic coupling is determined by spin engineering multilayered structures comprised of trilayers of Ni80Co20/Ru/Ni80Co20 in which one of the Ni80Co20 layers is strongly antiferromagnetically pinned to a Co layer. Oscillations in antiferromagnetic exchange coupling are measured in companion Ni80Cu20/Ru multilayers. The dependence of the exchange coupling strength on Ru thickness is well described by the Ruderman-Kittel-Kasuya-Yosida far-field range function, providing a direct measurement of this function through a transition metal.