Researchers from a collaborative effort between Université de Montréal, Linköping University, and École Polytechnique Fédérale de Lausanne have published a study that sheds new light on the factors influencing electrical resistivity in metals. The team, comprising Ao Wang, Junwen Yin, Félix Antoine Goudreault, Michel Côté, Olle Hellman, and Samuel Poncé, has investigated the complex interplay of thermal expansion and phonon anharmonicity on the phonon-limited resistivity of elemental metals. Their findings were published in the journal Physical Review B.
Electrical resistivity is a critical property in the energy industry, as it directly impacts the efficiency of power transmission and the performance of electrical devices. Understanding and accurately predicting resistivity in metals is therefore of great importance. Current first-principles calculations, which are based on the Boltzmann transport equation, often match experimental results but typically overlook the effects of thermal expansion and phonon anharmonicity.
The researchers found that thermal expansion and phonon anharmonicity have opposing effects on electron-phonon coupling, which in turn influences electrical resistivity. Thermal expansion enhances the coupling, leading to an overestimation of resistivity, while anharmonic effects reduce it. By incorporating both effects into their calculations, the team was able to provide a more comprehensive description of resistivity in elemental metals, specifically demonstrating this with lead (Pb), niobium (Nb), and aluminum (Al).
This research highlights the importance of considering both thermal expansion and phonon anharmonicity in predicting the electrical resistivity of metals. For the energy industry, this means more accurate modeling and better-informed material choices for conductors and other critical components. By refining our understanding of these fundamental processes, we can improve the efficiency and performance of a wide range of energy technologies.
The study, titled “Antagonistic impact of thermal expansion and phonon anharmonicity on the phonon-limited resistivity of elemental metals from first principles,” was published in Physical Review B, a journal dedicated to publishing original research on the understanding of collective phenomena in condensed matter and materials physics.
This article is based on research available at arXiv.