Tunable resistivity exponents in the metallic phase of epitaxial nickelates

TL;DR

This study investigates how epitaxial strain influences the electrical resistivity exponent in NdNiO3 thin films, revealing tunable behavior between Fermi and non-Fermi liquids and emphasizing the importance of disorder analysis.

Contribution

It demonstrates that epitaxial strain can tune the resistivity exponent in NdNiO3 films, highlighting the role of disorder in interpreting electronic behavior.

Findings

Resistivity exponent n varies from 1 to 3 with strain.

Strain-free films show linear resistivity, indicating Fermi liquid behavior.

Disorder significantly affects the resistivity exponent.

Abstract

We report a detailed analysis of the electrical resistivity exponent of thin films of NdNiO3 as a function of epitaxial strain. Strain-free thin-films show a linear dependence of the resistivity vs 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.