Influence of oxidic and metallic interfaces on the magnetic damping of Permalloy thin films
Sprache des Titels:
Englisch
Original Kurzfassung:
Magnetic damping within Ni 80 Fe 20 (Permalloy, Py) thin films is studied via temperature- and frequency-
dependent ferromagnetic resonance (FMR) experiments. While the Py thickness is kept constant at 20 nm, the
environment at the film interfaces was systematically varied by fabricating a set of Py thin films grown on
widely used substrates and capped with common layers, which are assumed to be suitable to prevent oxidation.
The resulting frequency and temperature dependence of the FMR linewidth significantly deviates from the
expected Gilbert-like behavior and especially for oxidic interfaces unwanted non-Gilbert-like contributions to
the magnetic damping appear, in particular, at low temperatures. In contrast, metallic capping layers avoid
non-Gilbert-like contributions. In particular, Py sandwiched in between Al metallic capping and buffer layers
exhibits negligible inhomogeneous FMR linewidth broadening and a very small, purely Gilbert-like contribution
of ? = 0.0066(2) down to the lowest temperature