Tunable resistivity exponents in the metallic phase of epitaxial nickelates

We report a detailed analysis of the electrical resistivity exponent of thin films of NdNiO 3 as a function of epitaxial strain. Thin films under low strain conditions show a linear dependence of the resistivity versus temperature, consistent with a classical Fermi gas ruled by electron-phonon interactions. In addition, the apparent temperature exponent, n , can be tuned with the epitaxial strain between n = 1 and n = 3. We discuss the critical role played by quenched random disorder in the value of n . Our work shows that the assignment of Fermi/Non-Fermi liquid behaviour based on experimentally obtained resistivity exponents requires an in-depth analysis of the degree of disorder in the material. Strong electronic correlations in rare-earth nickelates make them prone to unconventional behaviour but extrinsic effects hamper the interpretation of data. Guo et al. show that apparent non-Fermi liquid transport in NdNiO 3 is tuned by strain and disorder, suggesting a more conventional origin.