Remarkable suppression of lattice thermal conductivity by electron-phonon scattering in iridium dioxide nanowires

The well-known electrocatalyst iridium dioxide (IrO2) has recently shown interesting topological and spin transport properties with potential applications as electrodes and spin injector/detector in oxide-based electronic and spintronic devices. So far, no study has been reported on its thermal properties that could disclose important aspects of electron and phonon interactions. Through combined experimental and modeling efforts, here we show rather high thermal conductivity of IrO2 that is mainly attributed to phonon transport. Analysis indicates that the large lattice contribution results from the strong interatomic bonding and large difference in the atomic mass between iridium and oxygen. Interestingly, it is found that electron-phonon scattering plays a significant role and leads to a remarkable reduction in the lattice thermal conductivity. (C) 2021 Elsevier Ltd. All rights reserved.