The discovery of superconductivity in bilayer nickel oxides has revived an intense effort to understand the potential of high-temperature superconductivity in these materials and their relation to cuprate superconductors. In this work, we investigate the growth and properties of bilayer ${\mathrm{La}}_3{\mathrm{Ni}}_2{\mathrm{O}}_7$ thin films as a function of substrate, oxygen treatment, and applied pressure in order to study the evolution of transport properties. We report epitaxial growth of ${\mathrm{La}}_3{\mathrm{Ni}}_2{\mathrm{O}}_7$ thin films on ${\mathrm{LaAlO}}_3$ (LAO) (001) and ${\mathrm{SrLaAlO}}_4$ (SLAO) (001) substrates, and the effects of ex situ annealing in a high-pressure furnace under an oxygen-rich environment (15 bar). Transport measurements show that the ${\mathrm{La}}_3{\mathrm{Ni}}_2{\mathrm{O}}_7$ thin films on LAO(001) exhibit Fermi-liquid-like metallic behavior with a slight Kondo-like upturn at low temperatures, which evolves with the application of modest hydrostatic pressures toward non-Fermi-liquid behavior with a temperature dependence of resistance approaching $\sim T^{1.4}$ at 1.41 GPa. The ability to tune the normal state resistivity of ${\mathrm{La}}_3{\mathrm{Ni}}_2{\mathrm{O}}_7$ films to display non-Fermi-liquid behavior under such a modest hydrostatic pressure range—only 6–8 % of that typically applied via diamond anvil cell in ${\mathrm{La}}_3{\mathrm{Ni}}_2{\mathrm{O}}_7$ single crystals to achieve comparable effects—is both noteworthy and unexpected. These findings imply the strong tunability of ${\mathrm{La}}_3{\mathrm{Ni}}_2{\mathrm{O}}_7$ thin film under epitaxial strain and hydrostatic pressure leading to exotic transport behavior at low temperatures.

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• Electrical conductivity
• Electronic structure
• Quantum criticality
• Laser ablation
• Non-Fermi-liquid theory
• Strain engineering