Recently, research in solid state physics concentrates on the influence of spin-orbit coupling (SOC) in transition metal oxides (TMO). While systems with partially filled 5d-orbitals are determined by SOC, its effect on 4d elements is still under discussion. A novel theory [1] considers the magnetism in TMO systems with such intermediate strong SOC. Following its predictions, we performed inelastic neutron scattering experiments on the model system Ca2RuO4 and observed a magnetic dispersion that is distinct different to conventional magnetism. It features a longitudinal magnon mode, a defining aspect of the theory.Having established this amplitude mode, we plan to follow its evolution upon Sr-substitution, and thus investigate the influence of SOC during the transition from an anti-ferromagnet to a metal. We propose to investigate the evolution of magnetic dispersion as a function of Sr-substitution, using the thermal triple axis spectrometer IN8 in its Flatcone modification.---[1] G. Khaliullin PRL 111, 197201 (2013)