  SrRuO3 (SRO) is an itinerant ferromagnet with strong coupling between the
charge, spin, and lattice degrees of freedom. This strong coupling suggests
that the electronic and magnetic behaviors of SRO are highly susceptible to
changes in the lattice distortion. Here we show how the spin interaction and
resultant magnon formation change with the modification in the crystallographic
orientation. We fabricated SRO epitaxial thin films with (100), (110), and
(111) surface orientations, to systematically modulate the spin interaction and
spin dimensionality. The reduced spin dimensionality and enhanced exchange
interaction in the (111)-oriented SRO thin film significantly suppresses magnon
formation. Our study comprehensively demonstrates the facile tunability of
magnon formation and spin interaction in correlated oxide thin films.
