Origins of bad-metal conductivity and the insulator–metal transition in the rare-earth nickelates
For most metals, increasing temperature (T) or disorder hastens electron scattering. The electronic conductivity (σ) decreases as T rises because electrons are more rapidly scattered by lattice vibrations. The value of σ decreases as disorder increases because electrons are more rapidly scattered by...
| Main Authors: | , , , |
|---|---|
| Other Authors: | |
| Format: | Article |
| Published: |
Springer Nature
2017
|
| Online Access: | http://hdl.handle.net/1721.1/111849 https://orcid.org/0000-0003-3116-6719 |
| _version_ | 1826209992311570432 |
|---|---|
| author | Ha, Sieu D. Silevitch, D. M. Ramanathan, Shriram Jaramillo, Rafael |
| author2 | Massachusetts Institute of Technology. Department of Materials Science and Engineering |
| author_facet | Massachusetts Institute of Technology. Department of Materials Science and Engineering Ha, Sieu D. Silevitch, D. M. Ramanathan, Shriram Jaramillo, Rafael |
| author_sort | Ha, Sieu D. |
| collection | MIT |
| description | For most metals, increasing temperature (T) or disorder hastens electron scattering. The electronic conductivity (σ) decreases as T rises because electrons are more rapidly scattered by lattice vibrations. The value of σ decreases as disorder increases because electrons are more rapidly scattered by imperfections in the material. This is the scattering rate hypothesis, which has guided our understanding of metal conductivity for over a century. However, for so-called bad metals with very low σ this hypothesis predicts scattering rates so high as to conflict with Heisenberga's uncertainty principle. Bad-metal conductivity has remained a puzzle since its initial discovery in the 1980s in high-temperature superconductors. Here we introduce the rare-earth nickelates (RNiO₃, R = rare-earth) as a class of bad metals. We study SmNiO₃ thin films using infrared spectroscopy while varying T and disorder. We show that the interaction between lattice distortions and Ni-O covalence explains bad-metal conductivity and the insulator-metal transition. This interaction shifts spectral weight over the large energy scale established by the Ni-O orbital interaction, thus enabling very low σ without violating the uncertainty principle. |
| first_indexed | 2024-09-23T14:38:53Z |
| format | Article |
| id | mit-1721.1/111849 |
| institution | Massachusetts Institute of Technology |
| last_indexed | 2024-09-23T14:38:53Z |
| publishDate | 2017 |
| publisher | Springer Nature |
| record_format | dspace |
| spelling | mit-1721.1/1118492022-10-01T21:55:38Z Origins of bad-metal conductivity and the insulator–metal transition in the rare-earth nickelates Ha, Sieu D. Silevitch, D. M. Ramanathan, Shriram Jaramillo, Rafael Massachusetts Institute of Technology. Department of Materials Science and Engineering Jaramillo, Rafael For most metals, increasing temperature (T) or disorder hastens electron scattering. The electronic conductivity (σ) decreases as T rises because electrons are more rapidly scattered by lattice vibrations. The value of σ decreases as disorder increases because electrons are more rapidly scattered by imperfections in the material. This is the scattering rate hypothesis, which has guided our understanding of metal conductivity for over a century. However, for so-called bad metals with very low σ this hypothesis predicts scattering rates so high as to conflict with Heisenberga's uncertainty principle. Bad-metal conductivity has remained a puzzle since its initial discovery in the 1980s in high-temperature superconductors. Here we introduce the rare-earth nickelates (RNiO₃, R = rare-earth) as a class of bad metals. We study SmNiO₃ thin films using infrared spectroscopy while varying T and disorder. We show that the interaction between lattice distortions and Ni-O covalence explains bad-metal conductivity and the insulator-metal transition. This interaction shifts spectral weight over the large energy scale established by the Ni-O orbital interaction, thus enabling very low σ without violating the uncertainty principle. United States. Army Research Office (Grant W911-NF-09-1-0398) National Science Foundation (U.S.) (Grant DMR-0952794) National Science Foundation (U.S.) (Grant DMR-1206519) 2017-10-13T21:03:56Z 2017-10-13T21:03:56Z 2014-03 2013-07 2017-10-12T12:52:17Z Article http://purl.org/eprint/type/JournalArticle 1745-2473 1745-2481 http://hdl.handle.net/1721.1/111849 Jaramillo, R. et al. “Origins of Bad-Metal Conductivity and the Insulator–metal Transition in the Rare-Earth Nickelates.” Nature Physics 10, 4 (March 2014): 304–307 © 2017 Macmillan Publishers Limited, part of Springer Nature https://orcid.org/0000-0003-3116-6719 http://dx.doi.org/10.1038/NPHYS2907 Nature Physics Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf Springer Nature arXiv |
| spellingShingle | Ha, Sieu D. Silevitch, D. M. Ramanathan, Shriram Jaramillo, Rafael Origins of bad-metal conductivity and the insulator–metal transition in the rare-earth nickelates |
| title | Origins of bad-metal conductivity and the insulator–metal transition in the rare-earth nickelates |
| title_full | Origins of bad-metal conductivity and the insulator–metal transition in the rare-earth nickelates |
| title_fullStr | Origins of bad-metal conductivity and the insulator–metal transition in the rare-earth nickelates |
| title_full_unstemmed | Origins of bad-metal conductivity and the insulator–metal transition in the rare-earth nickelates |
| title_short | Origins of bad-metal conductivity and the insulator–metal transition in the rare-earth nickelates |
| title_sort | origins of bad metal conductivity and the insulator metal transition in the rare earth nickelates |
| url | http://hdl.handle.net/1721.1/111849 https://orcid.org/0000-0003-3116-6719 |
| work_keys_str_mv | AT hasieud originsofbadmetalconductivityandtheinsulatormetaltransitionintherareearthnickelates AT silevitchdm originsofbadmetalconductivityandtheinsulatormetaltransitionintherareearthnickelates AT ramanathanshriram originsofbadmetalconductivityandtheinsulatormetaltransitionintherareearthnickelates AT jaramillorafael originsofbadmetalconductivityandtheinsulatormetaltransitionintherareearthnickelates |