Enhanced Electron Correlation and Significantly Suppressed Thermal Conductivity in Dirac Nodal‐Line Metal Nanowires by Chemical Doping. Issue 2 (27th November 2022)

• Record Type: Journal Article
• Authors: Coughlin, Amanda L.; Pan, Zhiliang; Hong, Jeonghoon; Zhang, Tongxie; Zhan, Xun; Wu, Wenqian; Xie, Dongyue; Tong, Tian; Ruch, Thomas; Heremans, Jean J.; Bao, Jiming; Fertig, Herbert A.; Wang, Jian; Kim, Jeongwoo; Zhu, Hanyu; Li, Deyu; Zhang, Shixiong
• Is Part Of: Advanced science. Volume 10:Issue 2(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-11-27
• Subjects: 5d transition metal oxides -- electron correlation -- iridium dioxide -- thermal conductivity; Science -- Periodicals; 505
• DOI: 10.1002/advs.202204424
• Languages: English
• ISSNs: 2198-3844

Abstract

Abstract: Enhancing electron correlation in a weakly interacting topological system has great potential to promote correlated topological states of matter with extraordinary quantum properties. Here, the enhancement of electron correlation in a prototypical topological metal, namely iridium dioxide (IrO2 ), via doping with 3d transition metal vanadium is demonstrated. Single‐crystalline vanadium‐doped IrO2 nanowires are synthesized through chemical vapor deposition where the nanowire yield and morphology are improved by creating rough surfaces on substrates. Vanadium doping leads to a dramatic decrease in Raman intensity without notable peak broadening, signifying the enhancement of electron correlation. The enhanced electron correlation is further evidenced by transport studies where the electrical resistivity is greatly increased and follows an unusual T $\sqrt T $ dependence on the temperature ( T ). The lattice thermal conductivity is suppressed by an order of magnitude via doping even at room temperature where phonon‐impurity scattering becomes less important. Density functional theory calculations suggest that the remarkable reduction of thermal conductivity arises from the complex phonon dispersion and reduced energy gap between phonon branches, which greatly enhances phase space for phonon–phonon Umklapp scattering. This work demonstrates a unique system combining 3d and 5d transition metals in isostructural materials to enrich the system with various types of interactions. Abstract : Enhancement of electron correlations in topological metal IrO2 nanowires is achieved by doping with 3d transition metal vanadium, as evidenced by a dramatic decrease in Raman intensity and unusual temperature dependence of resistivity. The lattice thermal conductivity is suppressed by an order of magnitude via doping due to the complex phonon dispersion and reduced energy gap between phonon branches.