1
|
Zheng LM, Wang XR, Lü WM, Li CJ, Paudel TR, Liu ZQ, Huang Z, Zeng SW, Han K, Chen ZH, Qiu XP, Li MS, Yang S, Yang B, Chisholm MF, Martin LW, Pennycook SJ, Tsymbal EY, Coey JMD, Cao WW. Ambipolar ferromagnetism by electrostatic doping of a manganite. Nat Commun 2018; 9:1897. [PMID: 29765044 PMCID: PMC5953920 DOI: 10.1038/s41467-018-04233-5] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 04/12/2018] [Indexed: 11/09/2022] Open
Abstract
Complex-oxide materials exhibit physical properties that involve the interplay of charge and spin degrees of freedom. However, an ambipolar oxide that is able to exhibit both electron-doped and hole-doped ferromagnetism in the same material has proved elusive. Here we report ambipolar ferromagnetism in LaMnO3, with electron-hole asymmetry of the ferromagnetic order. Starting from an undoped atomically thin LaMnO3 film, we electrostatically dope the material with electrons or holes according to the polarity of a voltage applied across an ionic liquid gate. Magnetotransport characterization reveals that an increase of either electron-doping or hole-doping induced ferromagnetic order in this antiferromagnetic compound, and leads to an insulator-to-metal transition with colossal magnetoresistance showing electron-hole asymmetry. These findings are supported by density functional theory calculations, showing that strengthening of the inter-plane ferromagnetic exchange interaction is the origin of the ambipolar ferromagnetism. The result raises the prospect of exploiting ambipolar magnetic functionality in strongly correlated electron systems.
Collapse
Affiliation(s)
- L M Zheng
- Condensed Matter Science and Technology Institute, School of Science, Harbin Institute of Technology, Harbin, 150081, China
| | - X Renshaw Wang
- School of Physical and Mathematical Sciences & School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, 639798, Singapore.
| | - W M Lü
- Condensed Matter Science and Technology Institute, School of Science, Harbin Institute of Technology, Harbin, 150081, China.
| | - C J Li
- Department of Materials Science and Engineering, National University of Singapore, Singapore, 117575, Singapore
| | - T R Paudel
- Department of Physics and Astronomy & Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, Nebraska, 68588, USA
| | - Z Q Liu
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Z Huang
- NUSNNI-NanoCore, National University of Singapore, Singapore, 117411, Singapore
| | - S W Zeng
- NUSNNI-NanoCore, National University of Singapore, Singapore, 117411, Singapore
| | - Kun Han
- NUSNNI-NanoCore, National University of Singapore, Singapore, 117411, Singapore
| | - Z H Chen
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA, 94720, USA.,Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.,School of Materials Science and Engineering, Harbin Institute of Technology, Shenzhen, Guangzhou, 518055, China
| | - X P Qiu
- Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology & Pohl Institute of Solid State Physics & School of Physics Science and Engineering, Tongji University, Shanghai, 200092, China
| | - M S Li
- Department of Materials Science and Engineering, National University of Singapore, Singapore, 117575, Singapore
| | - Shize Yang
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - B Yang
- Condensed Matter Science and Technology Institute, School of Science, Harbin Institute of Technology, Harbin, 150081, China
| | - Matthew F Chisholm
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - L W Martin
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA, 94720, USA.,Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - S J Pennycook
- Department of Materials Science and Engineering, National University of Singapore, Singapore, 117575, Singapore
| | - E Y Tsymbal
- Department of Physics and Astronomy & Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, Nebraska, 68588, USA
| | - J M D Coey
- School of Physics, Trinity College, Dublin, 2, Ireland.,Faculty of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - W W Cao
- Condensed Matter Science and Technology Institute, School of Science, Harbin Institute of Technology, Harbin, 150081, China.,Department of Mathematics and Materials Research Institute, The Pennsylvania State University, University Park, PA, 16802, USA
| |
Collapse
|
2
|
Chen Y, Xing W, Wang X, Shen B, Yuan W, Su T, Ma Y, Yao Y, Zhong J, Yun Y, Xie XC, Jia S, Han W. Role of Oxygen in Ionic Liquid Gating on Two-Dimensional Cr 2Ge 2Te 6: A Non-oxide Material. ACS APPLIED MATERIALS & INTERFACES 2018; 10:1383-1388. [PMID: 29251913 DOI: 10.1021/acsami.7b14795] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Ionic liquid gating can markedly modulate a material's carrier density so as to induce metallization, superconductivity, and quantum phase transitions. One of the main issues is whether the mechanism of ionic liquid gating is an electrostatic field effect or an electrochemical effect, especially for oxide materials. Recent observation of the suppression of the ionic liquid gate-induced metallization in the presence of oxygen for oxide materials suggests the electrochemical effect. However, in more general scenarios, the role of oxygen in the ionic liquid gating effect is still unclear. Here, we perform ionic liquid gating experiments on a non-oxide material: two-dimensional ferromagnetic Cr2Ge2Te6. Our results demonstrate that despite the large increase of the gate leakage current in the presence of oxygen, the oxygen does not affect the ionic liquid gating effect on the channel resistance of Cr2Ge2Te6 devices (<5% difference), which suggests the electrostatic field effect as the mechanism on non-oxide materials. Moreover, our results show that ionic liquid gating is more effective on the modulation of the channel resistances compared to the back gating across the 300 nm thick SiO2.
Collapse
Affiliation(s)
- Yangyang Chen
- International Center for Quantum Materials, School of Physics, Peking University , Beijing 100871, PR China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, PR China
| | - Wenyu Xing
- International Center for Quantum Materials, School of Physics, Peking University , Beijing 100871, PR China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, PR China
| | - Xirui Wang
- International Center for Quantum Materials, School of Physics, Peking University , Beijing 100871, PR China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, PR China
| | - Bowen Shen
- International Center for Quantum Materials, School of Physics, Peking University , Beijing 100871, PR China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, PR China
| | - Wei Yuan
- International Center for Quantum Materials, School of Physics, Peking University , Beijing 100871, PR China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, PR China
| | - Tang Su
- International Center for Quantum Materials, School of Physics, Peking University , Beijing 100871, PR China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, PR China
| | - Yang Ma
- International Center for Quantum Materials, School of Physics, Peking University , Beijing 100871, PR China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, PR China
| | - Yunyan Yao
- International Center for Quantum Materials, School of Physics, Peking University , Beijing 100871, PR China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, PR China
| | - Jiangnan Zhong
- International Center for Quantum Materials, School of Physics, Peking University , Beijing 100871, PR China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, PR China
| | - Yu Yun
- International Center for Quantum Materials, School of Physics, Peking University , Beijing 100871, PR China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, PR China
| | - X C Xie
- International Center for Quantum Materials, School of Physics, Peking University , Beijing 100871, PR China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, PR China
| | - Shuang Jia
- International Center for Quantum Materials, School of Physics, Peking University , Beijing 100871, PR China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, PR China
| | - Wei Han
- International Center for Quantum Materials, School of Physics, Peking University , Beijing 100871, PR China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, PR China
| |
Collapse
|
3
|
Bisri SZ, Shimizu S, Nakano M, Iwasa Y. Endeavor of Iontronics: From Fundamentals to Applications of Ion-Controlled Electronics. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2017; 29:1607054. [PMID: 28582588 DOI: 10.1002/adma.201607054] [Citation(s) in RCA: 184] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2016] [Revised: 02/16/2017] [Indexed: 05/28/2023]
Abstract
Iontronics is a newly emerging interdisciplinary concept which bridges electronics and ionics, covering electrochemistry, solid-state physics, electronic engineering, and biological sciences. The recent developments of electronic devices are highlighted, based on electric double layers formed at the interface between ionic conductors (but electronically insulators) and various electronic conductors including organics and inorganics (oxides, chalcogenide, and carbon-based materials). Particular attention is devoted to electric-double-layer transistors (EDLTs), which are producing a significant impact, particularly in electrical control of phase transitions, including superconductivity, which has been difficult or impossible in conventional all-solid-state electronic devices. Besides that, the current state of the art and the future challenges of iontronics are also reviewed for many applications, including flexible electronics, healthcare-related devices, and energy harvesting.
Collapse
Affiliation(s)
- Satria Zulkarnaen Bisri
- RIKEN Center for Emergent Matter Science (CEMS), 2-1 Hirosawa, Wako-shi, Saitama, 351-0198, Japan
| | - Sunao Shimizu
- RIKEN Center for Emergent Matter Science (CEMS), 2-1 Hirosawa, Wako-shi, Saitama, 351-0198, Japan
| | - Masaki Nakano
- Quantum Phase Electronic Center (QPEC) and Department of Applied Physics, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
| | - Yoshihiro Iwasa
- RIKEN Center for Emergent Matter Science (CEMS), 2-1 Hirosawa, Wako-shi, Saitama, 351-0198, Japan
- Quantum Phase Electronic Center (QPEC) and Department of Applied Physics, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
| |
Collapse
|
4
|
Abbas K, Hwang J, Bae G, Choi H, Kang DJ. Control of Multilevel Resistance in Vanadium Dioxide by Electric Field Using Hybrid Dielectrics. ACS APPLIED MATERIALS & INTERFACES 2017; 9:13571-13576. [PMID: 28351132 DOI: 10.1021/acsami.6b16424] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We investigate the effect of electric field on VO2 back-gated field effect transistor (FET) devices. Using hybrid dielectric layers, we demonstrate the highest resistance modulation on the order of 102 in VO2 at a positive gate bias of 80 V (1.6 MV/cm). VO2 FET devices are prepared on SiO2 substrates of different thicknesses (100-300 nm) and hybrid dielectric layers of Al2O3/SiO2 (500 nm). For thicknesses less than 300 nm, no electric-field effects are observed, whereas for a 300 nm thickness, a small decrease in resistance is observed under a 0.2 MV/cm electric field. Under the electrostatic effect, the carrier concentration increases in VO2 devices, decreasing the resistance and the transition temperature from 66.75 to 64 °C. The leakage analysis shows that the interface quality of VO2 films on hybrid dielectric layers can be further improved. These studies suggest a multilevel fast resistance switching with the electric field and give an insight into the gate-source leakage current, which limits the phase transition in VO2 in an electric field.
Collapse
Affiliation(s)
- Kaleem Abbas
- Department of Physics and Energy Science, Sungkyunkwan University , 2066, Seobu-ro, Jangan-gu, Suwon 16419, Gyeoggi-do, Republic of Korea
| | - Jaeseok Hwang
- Department of Physics and Energy Science, Sungkyunkwan University , 2066, Seobu-ro, Jangan-gu, Suwon 16419, Gyeoggi-do, Republic of Korea
| | - Garam Bae
- Department of Physics and Energy Science, Sungkyunkwan University , 2066, Seobu-ro, Jangan-gu, Suwon 16419, Gyeoggi-do, Republic of Korea
| | - Hongsoo Choi
- Department of Robotics Engineering, Daegu Gyeongbuk Institute of Science and Technology (DGIST) , 711-873 Daegu, Republic of Korea
| | - Dae Joon Kang
- Department of Physics and Energy Science, Sungkyunkwan University , 2066, Seobu-ro, Jangan-gu, Suwon 16419, Gyeoggi-do, Republic of Korea
| |
Collapse
|
5
|
A steep-slope transistor based on abrupt electronic phase transition. Nat Commun 2015; 6:7812. [PMID: 26249212 PMCID: PMC4918311 DOI: 10.1038/ncomms8812] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 06/14/2015] [Indexed: 11/10/2022] Open
Abstract
Collective interactions in functional materials can enable novel macroscopic properties like insulator-to-metal transitions. While implementing such materials into field-effect-transistor technology can potentially augment current state-of-the-art devices by providing unique routes to overcome their conventional limits, attempts to harness the insulator-to-metal transition for high-performance transistors have experienced little success. Here, we demonstrate a pathway for harnessing the abrupt resistivity transformation across the insulator-to-metal transition in vanadium dioxide (VO2), to design a hybrid-phase-transition field-effect transistor that exhibits gate controlled steep (‘sub-kT/q') and reversible switching at room temperature. The transistor design, wherein VO2 is implemented in series with the field-effect transistor's source rather than into the channel, exploits negative differential resistance induced across the VO2 to create an internal amplifier that facilitates enhanced performance over a conventional field-effect transistor. Our approach enables low-voltage complementary n-type and p-type transistor operation as demonstrated here, and is applicable to other insulator-to-metal transition materials, offering tantalizing possibilities for energy-efficient logic and memory applications. The intrinsic properties of conventional semiconductors limits the speed and efficiency of field-effect transistors. Here, the authors take advantage of the insulator-to-metal transition in vanadium dioxide to create a transistor with reversible and steep-slope switching at room temperature.
Collapse
|
6
|
Nath R, Raychaudhuri AK. Control of co-existing phases and charge transport in a nanostructured manganite film by field effects with an electric double layer as the gate dielectric. RSC Adv 2015. [DOI: 10.1039/c5ra09081d] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
We report bipolar control of co-existing phases in a nanostructured film of manganite. The field-effect-induced charge alters the characteristic temperatures and the relative fraction of the co-existing phases with an exponential dependence on the gate bias.
Collapse
Affiliation(s)
- Rajib Nath
- Dept. of Condensed Matter Physics & Material Sciences
- S. N. Bose National Centre for Basic Sciences
- Kolkata-98
- India
| | - A. K. Raychaudhuri
- Dept. of Condensed Matter Physics & Material Sciences
- S. N. Bose National Centre for Basic Sciences
- Kolkata-98
- India
| |
Collapse
|
7
|
Ichimura T, Fujiwara K, Tanaka H. Dual field effects in electrolyte-gated spinel ferrite: electrostatic carrier doping and redox reactions. Sci Rep 2014; 4:5818. [PMID: 25056718 PMCID: PMC4108912 DOI: 10.1038/srep05818] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Accepted: 07/08/2014] [Indexed: 11/08/2022] Open
Abstract
Controlling the electronic properties of functional oxide materials via external electric fields has attracted increasing attention as a key technology for next-generation electronics. For transition-metal oxides with metallic carrier densities, the electric-field effect with ionic liquid electrolytes has been widely used because of the enormous carrier doping capabilities. The gate-induced redox reactions revealed by recent investigations have, however, highlighted the complex nature of the electric-field effect. Here, we use the gate-induced conductance modulation of spinel ZnxFe₃₋xO₄ to demonstrate the dual contributions of volatile and non-volatile field effects arising from electronic carrier doping and redox reactions. These two contributions are found to change in opposite senses depending on the Zn content x; virtual electronic and chemical field effects are observed at appropriate Zn compositions. The tuning of field-effect characteristics via composition engineering should be extremely useful for fabricating high-performance oxide field-effect devices.
Collapse
Affiliation(s)
- Takashi Ichimura
- The Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka 567-0047, Japan
| | - Kohei Fujiwara
- The Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka 567-0047, Japan
| | - Hidekazu Tanaka
- The Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka 567-0047, Japan
| |
Collapse
|
8
|
High magnetic field phase diagram in electron-doped manganites La(0.4)Ca(0.6)Mn(1-y)Cr(y)O3. Sci Rep 2014; 4:4902. [PMID: 24811441 PMCID: PMC4014982 DOI: 10.1038/srep04902] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Accepted: 04/10/2014] [Indexed: 12/02/2022] Open
Abstract
We report the charge-order to ferromagnetic phase transition induced by pulsed high magnetic field and impurity doping effects in manganites La0.4Ca0.6(Mn1−yCry)O3 (0 ≤ y ≤ 0.2). Significant charge-order suppression and ferromagnetic tendency upon the Cr3+-doping are evidenced, and three different ground states are identified, namely the charge-order state, the phase separated state, and the spin-glass like state. Phase diagram in the H-y plane at 4.2 K is determined by the high magnetic field study, in which the charge-order and ferromagnetic phase boundary is clearly figured out. The critical magnetic field for melting the charge-order phase of La0.4Ca0.6MnO3 is revealed to reach up to 46 T at 4.2 K. Interestingly, distinct responses of the three states to the high magnetic field are observed, indicating the special physics regarding the charge order melting process in each state. The mechanism of the doping induced charge-order suppression and ferromagnetism promotion can be understood by the competition between the antiferromagnetic interaction of Cr-Mn and local enhancement of electron hopping by Cr3+.
Collapse
|