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Rybkin AG, Tarasov AV, Rybkina AA, Usachov DY, Petukhov AE, Eryzhenkov AV, Pudikov DA, Gogina AA, Klimovskikh II, Di Santo G, Petaccia L, Varykhalov A, Shikin AM. Sublattice Ferrimagnetism in Quasifreestanding Graphene. PHYSICAL REVIEW LETTERS 2022; 129:226401. [PMID: 36493449 DOI: 10.1103/physrevlett.129.226401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 08/17/2022] [Accepted: 10/14/2022] [Indexed: 06/17/2023]
Abstract
We show that graphene can be magnetized by coupling to a ferromagnetic Co film through a Au monolayer. The presence of dislocation loops under graphene leads to a ferrimagnetic ordering of moments in the two C sublattices. It is shown that the band gap of ∼80 meV in the K[over ¯] point has a magnetic nature and exists for ferrimagnetic ordering. Interplay between Rashba and exchange couplings is evidenced by spin splitting asymmetry in spin-ARPES measurements and fully supported by DFT calculation of a (9×9) unit cell. Owing to sign-opposite Berry curvatures for K[over ¯] and K[over ¯]^{'} valleys, the synthesized system is promising for the realization of a circular dichroism Hall effect.
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Affiliation(s)
- Artem G Rybkin
- St. Petersburg State University, 198504 St. Petersburg, Russia
| | - Artem V Tarasov
- St. Petersburg State University, 198504 St. Petersburg, Russia
| | - Anna A Rybkina
- St. Petersburg State University, 198504 St. Petersburg, Russia
| | | | | | | | | | | | - Ilya I Klimovskikh
- St. Petersburg State University, 198504 St. Petersburg, Russia
- Center for Advanced Mesoscience and Nanotechnology, Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Russia
| | - Giovanni Di Santo
- Elettra Sincrotrone Trieste, Strada Statale 14 km 163.5, 34149 Trieste, Italy
| | - Luca Petaccia
- Elettra Sincrotrone Trieste, Strada Statale 14 km 163.5, 34149 Trieste, Italy
| | - Andrei Varykhalov
- Helmholtz-Zentrum Berlin für Materialien und Energie, Elektronenspeicherring BESSY II, Albert-Einstein-Str. 15, D-12489 Berlin, Germany
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Lian H, Cheng X, Hao H, Han J, Lau MT, Li Z, Zhou Z, Dong Q, Wong WY. Metal-containing organic compounds for memory and data storage applications. Chem Soc Rev 2022; 51:1926-1982. [PMID: 35083990 DOI: 10.1039/d0cs00569j] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
With the upcoming trend of Big Data era, some new types of memory technologies have emerged as substitutes for the traditional Si-based semiconductor memory devices, which are encountering severe scaling down technical obstacles. In particular, the resistance random access memory (RRAM) and magnetic random access memory (MRAM) hold great promise for the in-memory computing, which are regarded as the optimal strategy and pathway to solve the von Neumann bottleneck by high-throughput in situ data processing. As far as the active materials in RRAM and MRAM are concerned, organic semiconducting materials have shown increasing application perspectives in memory devices due to their rich structural diversity and solution processability. With the introduction of metal elements into the backbone of molecules, some new properties and phenomena will emerge accordingly. Consequently, the RRAM and MRAM devices based on metal-containing organic compounds (including the small molecular metal complexes, metallopolymers, metal-organic frameworks (MOFs) and organic-inorganic-hybrid perovskites (OIHPs)) have been widely explored and attracted intense attention. In this review, we highlight the fundamentals of RRAM and MRAM, as well as the research progress of the applications of metal-containing organic compounds in both RRAM and MRAM. Finally, we discuss the challenges and future directions for the research of organic RRAM and MRAM.
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Affiliation(s)
- Hong Lian
- MOE Key Laboratory of Advanced Display and System Applications, Shanghai University, 149 Yanchang Road, Jingan District, Shanghai 200072, China.,School of Mechanical & Electronic Engineering and Automation, Shanghai University, 99 Shangda Road, Baoshan District, Shanghai 200444, China. .,MOE Key Laboratory of Interface Science and Engineering in Advanced Materials, Taiyuan University of Technology, 79 Yingze West Street, Taiyuan, 030024, China
| | - Xiaozhe Cheng
- MOE Key Laboratory of Advanced Display and System Applications, Shanghai University, 149 Yanchang Road, Jingan District, Shanghai 200072, China.,MOE Key Laboratory of Interface Science and Engineering in Advanced Materials, Taiyuan University of Technology, 79 Yingze West Street, Taiyuan, 030024, China.,Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, China.
| | - Haotian Hao
- MOE Key Laboratory of Interface Science and Engineering in Advanced Materials, Taiyuan University of Technology, 79 Yingze West Street, Taiyuan, 030024, China
| | - Jinba Han
- MOE Key Laboratory of Interface Science and Engineering in Advanced Materials, Taiyuan University of Technology, 79 Yingze West Street, Taiyuan, 030024, China
| | - Mei-Tung Lau
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, China. .,The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen 518057, China
| | - Zikang Li
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, China. .,The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen 518057, China
| | - Zhi Zhou
- School of Chemistry and Materials Science, Hunan Agricultural University, Changsha 410128, China.
| | - Qingchen Dong
- MOE Key Laboratory of Advanced Display and System Applications, Shanghai University, 149 Yanchang Road, Jingan District, Shanghai 200072, China.,School of Mechanical & Electronic Engineering and Automation, Shanghai University, 99 Shangda Road, Baoshan District, Shanghai 200444, China. .,MOE Key Laboratory of Interface Science and Engineering in Advanced Materials, Taiyuan University of Technology, 79 Yingze West Street, Taiyuan, 030024, China
| | - Wai-Yeung Wong
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, China. .,The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen 518057, China
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Aboljadayel ROM, Ionescu A, Burton OJ, Cheglakov G, Hofmann S, Barnes CHW. Growth and Characterisation Studies of Eu 3O 4 Thin Films Grown on Si/SiO 2 and Graphene. NANOMATERIALS (BASEL, SWITZERLAND) 2021; 11:1598. [PMID: 34204525 PMCID: PMC8233992 DOI: 10.3390/nano11061598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 06/02/2021] [Accepted: 06/02/2021] [Indexed: 11/17/2022]
Abstract
We report the growth, structural and magnetic properties of the less studied Eu-oxide phase, Eu3O4, thin films grown on a Si/SiO2 substrate and Si/SiO2/graphene using molecular beam epitaxy. The X-ray diffraction scans show that highly textured crystalline Eu3O4(001) films are grown on both substrates, whereas the film deposited on graphene has a better crystallinity than that grown on the Si/SiO2 substrate. The SQUID measurements show that both films have a Curie temperature of ∼5.5±0.1 K, with a magnetic moment of ∼320 emu/cm3 at 2 K. The mixed valence of the Eu cations has been confirmed by the qualitative analysis of the depth-profile X-ray photoelectron spectroscopy measurements with the Eu2+:Eu3+ ratio of 28:72. However, surprisingly, our films show no metamagnetic behaviour as reported for the bulk and powder form. Furthermore, the microscopic optical images and Raman measurements show that the graphene underlayer remains largely intact after the growth of the Eu3O4 thin films.
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Affiliation(s)
- Razan O. M. Aboljadayel
- Cavendish Laboratory, Physics Department, University of Cambridge, Cambridge CB3 0HE, UK; (A.I.); (G.C.); (C.H.W.B.)
- Diamond Light Source, Didcot OX11 0DE, UK
| | - Adrian Ionescu
- Cavendish Laboratory, Physics Department, University of Cambridge, Cambridge CB3 0HE, UK; (A.I.); (G.C.); (C.H.W.B.)
| | - Oliver J. Burton
- Department of Engineering, University of Cambridge, Cambridge CB3 0FA, UK; (O.J.B.); (S.H.)
| | - Gleb Cheglakov
- Cavendish Laboratory, Physics Department, University of Cambridge, Cambridge CB3 0HE, UK; (A.I.); (G.C.); (C.H.W.B.)
| | - Stephan Hofmann
- Department of Engineering, University of Cambridge, Cambridge CB3 0FA, UK; (O.J.B.); (S.H.)
| | - Crispin H. W. Barnes
- Cavendish Laboratory, Physics Department, University of Cambridge, Cambridge CB3 0HE, UK; (A.I.); (G.C.); (C.H.W.B.)
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