Epitaxial thin films of pyrochlore iridate Bi₂₊ₓIr₂₋ᵧO₇₋δ: structure, defects and transport properties
| dc.contributor.author | Yang, W. C. | en |
| dc.contributor.author | Xie, Y. T. | en |
| dc.contributor.author | Zhu, W. K. | en |
| dc.contributor.author | Park, K. | en |
| dc.contributor.author | Chen, A. P. | en |
| dc.contributor.author | Losovyj, Y. | en |
| dc.contributor.author | Li, Z. | en |
| dc.contributor.author | Liu, H. M. | en |
| dc.contributor.author | Starr, M. | en |
| dc.contributor.author | Acosta, J. A. | en |
| dc.contributor.author | Tao, C. G. | en |
| dc.contributor.author | Li, N. | en |
| dc.contributor.author | Jia, Q. X. | en |
| dc.contributor.author | Heremans, Jean J. | en |
| dc.contributor.author | Zhang, S. X. | en |
| dc.contributor.department | Physics | en |
| dc.date.accessioned | 2017-08-14T15:40:44Z | en |
| dc.date.available | 2017-08-14T15:40:44Z | en |
| dc.date.issued | 2017-08-10 | en |
| dc.description.abstract | While pyrochlore iridate thin films are theoretically predicted to possess a variety of emergent topological properties, experimental verification of these predictions can be obstructed by the challenge in thin film growth. Here we report on the pulsed laser deposition and characterization of thin films of a representative pyrochlore compound Bi₂Ir₂O₇. The films were epitaxially grown on yttriastabilized zirconia substrates and have lattice constants that are a few percent larger than that of the bulk single crystals. The film composition shows a strong dependence on the oxygen partial pressure. Density-functional-theory calculations indicate the existence of BiIr antisite defects, qualitatively consistent with the high Bi: Ir ratio found in the films. Both Ir and Bi have oxidation states that are lower than their nominal values, suggesting the existence of oxygen deficiency. The iridate thin films show a variety of intriguing transport characteristics, including multiple charge carriers, logarithmic dependence of resistance on temperature, antilocalization corrections to conductance due to spin-orbit interactions, and linear positive magnetoresistance. | en |
| dc.description.sponsorship | We thank Professor J. Wang, Dr. Y. Wang, Prof. Y. Lan, Dr. C.-H. Chen and S. Cheema for fruitful discussions. S. X. Z. acknowledges start-up support from Indiana University (IU) College of Arts and Sciences. J. J. H. and Y. X. were supported for the transport measurements by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering under award DOE DE-FG02-08ER46532. K.P. is grateful to John W. Villanova for creating the initial pyrochlore structure and to Denis Demchenko for an advice in computation of formation energy, and was supported by U.S. National Science Foundation DMR-1206354, San Diego Supercomputer Center (SDSC) Comet and Gordon under DMR060009N, and Advanced Research Computing at Virginia Tech. We thank the IU Nanoscale Characterization Facility for access to the scanning electron microscope. XPS instrument at Nanoscale Characterization Facility of IU Nanoscience Center was funded by NSF Award DMR MRI-1126394. The X-ray diffraction facilities at the IU Molecular Structure Center was supported by NSF Grant No. CHE-1048613. The work at Los Alamos National Laboratory was supported by the NNSA's Laboratory Directed Research and Development Program and was performed, in part, at the Center for Integrated Nanotechnologies, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science. Los Alamos National Laboratory, an affirmative action equal opportunity employer, is operated by Los Alamos National Security, LLC, for the National Nuclear Security Administration of the U.S. Department of Energy under contract DE-AC52-06NA25396. | en |
| dc.format.mimetype | application/pdf | en |
| dc.identifier.doi | https://doi.org/10.1038/s41598-017-06785-w | en |
| dc.identifier.issn | 2045-2322 | en |
| dc.identifier.other | 7740 | en |
| dc.identifier.pmid | 28798487 | en |
| dc.identifier.uri | http://hdl.handle.net/10919/78700 | en |
| dc.identifier.volume | 7 | en |
| dc.language.iso | en_US | en |
| dc.publisher | Nature | en |
| dc.rights | Creative Commons Attribution 4.0 International | en |
| dc.rights.uri | http://creativecommons.org/licenses/by/4.0/ | en |
| dc.subject | total-energy calculations | en |
| dc.subject | time-reversal symmetry | en |
| dc.subject | spin-orbit interaction | en |
| dc.subject | wave basis-set | en |
| dc.subject | electron-interaction | en |
| dc.subject | iridium | en |
| dc.subject | metal | en |
| dc.subject | magnetoresistance | en |
| dc.subject | insulator | en |
| dc.subject | disorder | en |
| dc.title | Epitaxial thin films of pyrochlore iridate Bi₂₊ₓIr₂₋ᵧO₇₋δ: structure, defects and transport properties | en |
| dc.title.serial | Scientific Reports | en |
| dc.type | Article - Refereed | en |
| dc.type.dcmitype | Text | en |