In fabrication of magnetic spin valves and magnetic tunnel junctions (MTJ), ruthenium is extensively used as a means of coupling antiferromagnetically the magnetization in two ferromagnetic layers. Elemental cobalt has a high magnetostriction, which makes its use as an electrode in spintronic devices unsatisfactory. However, by alloying it with iron this is dramatically reduced and an 80% Co20% Fe composition is very commonly used. Further, although Co and Ru are miscible, when cobalt is alloyed with iron the chemical affinity between the two reduces the miscibility with ruthenium  and the interfaces are expected to be relatively sharp.The stability of the interface structure of sputtered Ru/Co80Fe20 layers during high temperature annealing has been studied recently  using grazing incidence X-ray scattering and interfaces have been shown to be stable up to at least 400◦ C. In this paper, we examine the interface structure of Ru/Co80Fe20 multilayers in more detail.
POLISH ACADEMY OF SCIENCES WARSAW
1 Dec 2007
Volume: 112 Issue: 6 Pages: 1243
ACTA PHYSICA POLONICA SERIES A