  We report on the resonant excitation of spin waves in micro-structured
magnetic thin films by surface acoustic waves (SAWs). The spin waves as well as
the acoustic waves are studied by micro-focused Brillouin light scattering
spectroscopy. Besides the excitation of the ferromagnetic resonance, a process
which does not fulfill momentum conservation, also the excitation of
finite-wavelength spin waves can be observed at low magnetic fields. Using
micromagnetic simulations, we verify that during this excitation both energy
and linear momentum are conserved and fully transferred from the SAW to the
spin wave.
