Tuning domain wall energy with strain: balancing anisotropy and exchange energies in Pt/Co/Ir

Measurements of the Co layer thickness dependence of saturation magnetisation, perpendicular magnetic anisotropy, and symmetric and antisymmetric exchange energies in Pt/Co/Ir thin films have been made to determine the relationship between these properties. We find that the enhancement of domain wall creep velocity under strain from piezoelectric transducers is increased in Pt/Co/Ir films with the thinnest Co layers (0.56 nm), in which the strain causes the smallest relative change in perpendicular magnetic anisotropy. We show how domain wall energy is predictive of the sensitivity of domain wall creep velocity to changes in strain, and thus provide a route to designing materials systems for optimum strain control.