  In elastically coupled multiferroic heterostructures that exhibit full domain
correlations between ferroelectric and ferromagnetic sub-systems, magnetic
domain walls are firmly pinned on top of ferroelectric domain boundaries. In
this work we investigate the influence of pinned magnetic domain walls on the
magnetization reversal process in a Co40Fe40B20 wedge film that is coupled to a
ferroelectric BaTiO3 substrate via interface strain transfer. We show that the
magnetic field direction can be used to select between two distinct
magnetization reversal mechanisms, namely (1) double switching events involving
alternate stripe domains at a time or (2) synchronized switching of all
domains. Furthermore, scaling of the switching fields with domain width and
film thickness is also found to depend on field orientation. These results are
explained by considering the dissimilar energies of the two types of pinned
magnetic domain walls that are formed in the system.
