Journal article
Systematic study of ferromagnetism in CrxSb2-xTe3 topological insulator thin films using electrical and optical techniques
- Abstract:
- Ferromagnetic ordering in a topological insulator can break time-reversal symmetry, realizing dissipationless electronic states in the absence of a magnetic field. The control of the magnetic state is of great importance for future device applications. We provide a detailed systematic study of the magnetic state in highly doped CrxSb2−xTe3 thin films using electrical transport, magneto-optic Kerr effect measurements and terahertz time domain spectroscopy, and also report an efficient electric gating of ferromagnetic order using the electrolyte ionic liquid [DEME][TFSI]. Upon increasing the Cr concentration from x = 0.15 to 0.76, the Curie temperature (Tc) was observed to increase by ~5 times to 176 K. In addition, it was possible to modify the magnetic moment by up to 50% with a gate bias variation of just ±3 V, which corresponds to an increase in carrier density by 50%. Further analysis on a sample with x = 0.76 exhibits a clear insulator-metal transition at Tc, indicating the consistency between the electrical and optical measurements. The direct correlation obtained between the carrier density and ferromagnetism - in both electrostatic and chemical doping - using optical and electrical means strongly suggests a carrier-mediated Ruderman-Kittel-Kasuya-Yoshida (RKKY) coupling scenario. Our low-voltage means of manipulating ferromagnetism, and consistency in optical and electrical measurements provides a way to realize exotic quantum states for spintronic and low energy magneto-electronic device applications.
- Publication status:
- Published
- Peer review status:
- Peer reviewed
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(Preview, Version of record, pdf, 3.3MB, Terms of use)
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- Publisher copy:
- 10.1038/s41598-018-35118-8
Authors
+ Engineering and Physical Sciences Research Council
More from this funder
- Funding agency for:
- Kamboj, V
- Llandro, J
- Duffy, L
- Beere, H
- Ritchie, D
- Barnes, C
- Grant:
- EP/J017671/1
- EP/J00412X/1
- EP/J017671/1
- EP/J017671/1
- EP/J00412X/1
+ SGPC Cambridge Commonwealth Trust
More from this funder
- Funding agency for:
- Singh, A
- Kamboj, V
- Grant:
- EP/J017671/1
- Publisher:
- Springer Nature
- Journal:
- Scientific Reports More from this journal
- Volume:
- 8
- Article number:
- 17024
- Publication date:
- 2018-11-19
- Acceptance date:
- 2018-10-27
- DOI:
- ISSN:
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2045-2322
- Keywords:
- Pubs id:
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pubs:935176
- UUID:
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uuid:e612ced2-673f-4c11-b939-443774cd3dbb
- Local pid:
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pubs:935176
- Source identifiers:
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935176
- Deposit date:
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2018-10-27
Terms of use
- Copyright holder:
- Singh, et al
- Copyright date:
- 2018
- Notes:
- This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
- Licence:
- CC Attribution (CC BY)
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