Tunable electron scattering mechanism in plasmonic SrMoO${}_3$ thin films

4d transition metal perovskite oxides serve as suitable testbeds for the study of strongly correlated metallic properties. Among these, $SrMo{O}_3$ (SMO) exhibits remarkable electrical conductivity at room temperature. The temperature-dependent resistivity $(\rho (T))$ exhibits a Fermi-liquid behavior below the transition temperature $T^{\ast }$, reflecting the dominant electron-electron interaction. Above $T^{\ast }$, electron-phonon interaction becomes more appreciable. In this study, we employed the power-law scaling of $\rho (T)$ to rigorously determine the $T^{\ast }$. We further demonstrate that the $T^{\ast }$ can be modified substantially by ~40 K in epitaxial thin films. It turns out that the structural quality determines $T^{\ast }$. Whereas the plasma frequency could be tuned by the change in the electron-electron interaction via the effective mass enhancement, we show that the plasmonic properties are more directly governed by the electron-impurity scattering. The facile control of the electron scattering mechanism through structural quality modulation can be useful for plasmonic sensing applications in the visible region.