Source Publication (e.g., journal title)
Nature Communications
Document Type
Article
Publication Date
1-8-2018
DOI
10.1038/s41467-017-02561-6
Abstract
Many-body effects produce deviations from the predictions of conventional band theory in quantum materials, leading to strongly correlated phases with insulating or bad metallic behavior. One example is the rare-earth nickelates RNiO3, which undergo metal-to-insulator transitions (MITs) whose origin is debated. Here, we combine total neutron scattering and broadband dielectric spectroscopy experiments to study and compare carrier dynamics and local crystal structure in LaNiO3 and NdNiO3. We find that the local crystal structure of both materials is distorted in the metallic phase, with slow, thermally activated carrier dynamics at high temperature. We further observe a sharp change in conductivity across the MIT in NdNiO3, accompanied by slight differences in the carrier hopping time. These results suggest that changes in carrier concentration drive the MIT through a polaronic mechanism, where the (bi)polaron liquid freezes into the insulating phase across the MIT temperature.
Recommended Citation
Shamblin, Jacob, Maximilian Heres , Haidong Zhou, Joshua Sangoro, Maik Lang, Joerg Neuefeind, J. A. Alonso, and Steven Johnston. “Experimental Evidence for Bipolaron Condensation as a Mechanism for the Metal-insulator Transition in Rare-earth Nickelates.” Nature Communications 9 (2018). http://doi.org/10.1038/s41467-017-02561-6.
Submission Type
Publisher's Version
Comments
This article was published openly thanks to the University of Tennessee Open Publishing Support Fund.
Licensed under a Creative Commons Attribution 4.0 International license.