  Ferromagnetic/Antiferromagnetic (FM/AFM) bilayers dynamics have been a recent
topic of interest due to the interaction occurring at the interface, where the
magnetic moments of the AFM can be imprinted into the FM, and the exchange bias
field can affect these dynamics. Here, we investigate Permalloy (Py) and NiO
(Py/NiO) hybrids and for comparison single Py films in the broad Py thickness
range varied from few nm to 200 nm by using static (Kerr effect) and dynamic
(spin waves) measurements along with micromagnetic simulations. We observe
hybrid modes between uniform (ferromagnetic resonance FMR, n=0) and
perpendicular standing spin waves (PSSWs, n=1, 2) and a clear enhancement of
the PSSWs modes frequencies upon interfacing Py with NiO both from experiments
and simulations. This enhancement becomes less pronounced as the thickness of
the film increases, demonstrating its interfacial origin rooted in the exchange
coupling between the FM and AFM layers. Besides, through micromagnetic
simulations, we investigate and correlate changes in spatial profiles of the
PSSWs with the interfacial exchange coupling. As the thickness is increased, we
see that the n=1 and n=2 modes begin to couple with the fundamental FMR mode,
resulting in asymmetric (with respect the Py layer center) modes. Our results
suggest that PSSWs detection in a ferromagnet offers a means of probing the
interfacial exchange coupling with the adjacent AFM layer. Furthermore, the
controlled spatial symmetry breaking by the AFM layer enables engineering of
PSSWs with different spatial profiles in the FM.
