  The dynamical response of magnetic domain walls to external magnetic fields
in ultra-thin multilayer magnetic films is determined not only by the
composition and thickness of the layers but also by the growth conditions.
Growth conditions can induce significant structural changes inside the layers
and at the interfaces between them, affecting in particular the dynamics of
domain walls, their mobility, elastic tension, and the pinning forces acting on
them. In this work, we focus specifically on the effect of Ir layer growth
pressure in Ta/Pt/Co/Ir/Ta ultra-thin multilayers films. Measurements of the DC
magnetic properties, domain wall velocity and domain morphology in the creep
regime for both constant and alternating field pulses, were performed for a
batch of samples where the Ir layer was grown at different pressures. We find
that the saturation magnetization, the effective anisotropy constant and the
domain wall surface tension grow with increasing pressure and saturate at a
threshold pressure, while the Dzyaloshinskii-Moriya field and the strength of
the disorder remain practically unaltered over the range of pressures
considered.
