Transition metals exemplify correlated electronic systems, where electron-electron ($e\text{−}e$) scattering often results in a quadratic temperature dependence of the electrical resistivity, $\rho (T)\propto T^2$. In ${\mathrm{SrVO}}_3$ (SVO), a material with a $V\text{−}3{\mathrm{d}}^1$ electronic configuration that ensures metallicity through narrow $3d\text{−}{\mathrm{t}}_{2g}$ bands, a $\rho (T)\propto T^2$ dependence has been reported. While traditionally attributed to $e\text{−}e$ scattering, recent studies suggest that electron-phonon ($e$-ph) interactions may play a significant role. To unravel the influence of phonon interactions on carrier transport in SVO, we present a comparative study of the transport and optical properties of SVO films with partial substitution of ${}^{16}\mathrm{O}$ ions by their heavier isotope, ${}^{18}\mathrm{O}$. Our findings reveal that ${}^{18}\mathrm{O}$ substitution induces a change in the slope of $d\rho (T)/dT$ at nominal fixed carrier density, highlighting the dominant contribution of $e$-ph coupling over $e\text{−}e$ scattering in determining $\rho (T)$. Furthermore, it is found that the ${}^{18}\mathrm{O}$ substitution softens the phonon lattice and promotes a reduction in plasma frequency and an increase in the carrier effective mass. These results indicate that the $e$-ph coupling strength increases upon ${}^{18}\mathrm{O}$ substitution. Our findings suggest that $e$-ph interactions may surpass $e\text{−}e$ scattering in governing the resistivity of metallic ionic lattices.

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• Electrical conductivity
• Electron-phonon coupling
• Phonons
• Plasmons
• Polarons
• Strongly correlated systems
• Resistivity measurements