Article
Chemistry, Multidisciplinary
Anushka Bansal, Nadire Nayir, Ke Wang, Patrick Rondomanski, Shruti Subramanian, Shalini Kumari, Joshua A. Robinson, Adri C. T. van Duin, Joan M. Redwing
Summary: Ultrathin 2D-GaNx can be formed by Ga intercalation into epitaxial graphene followed by nitridation. The influence of graphene layer thickness and chemical functionalization on Ga intercalation and 2D-GaNx formation is examined using experimental and theoretical studies.
Article
Chemistry, Multidisciplinary
Yuqing Song, Yaqi Gao, Xiaoting Liu, Jing Ma, Buhang Chen, Qin Xie, Xin Gao, Liming Zheng, Yan Zhang, Qingjie Ding, Kaicheng Jia, Luzhao Sun, Wendong Wang, Zhetong Liu, Bingyao Liu, Peng Gao, Hailin Peng, Tongbo Wei, Li Lin, Zhongfan Liu
Summary: Understanding the formation mechanism of transfer-related graphene wrinkles allows for the fabrication of wrinkle arrays without altering the crystalline orientation of the entire graphene film. The choice of transfer medium with poor wettability on the corrugated surface of graphene is key to the formation of wrinkles, providing a new way to modify the surface properties of graphene for potential applications.
ADVANCED MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Luzhao Sun, Buhang Chen, Wendong Wang, Yanglizhi Li, Xiongzhi Zeng, Haiyang Liu, Yu Liang, Zhenyong Zhao, Ali Cai, Rui Zhang, Yeshu Zhu, Yuechen Wang, Yuqing Song, Qingjie Ding, Xuan Gao, Hailin Peng, Zhenyu Li, Li Lin, Zhongfan Liu
Summary: This study found that trace amounts of oxygen enhance the interaction between graphene and Cu(111) substrate, eliminating misoriented graphene domains. Through a modified anomalous grain growth method and a self-designed pilot-scale CVD system, high-quality single-crystal graphene films were produced on Cu(111) foils in batch production. The findings and strategies provided in this work could accelerate the mass production of high-quality misorientation-free graphene films.
Article
Chemistry, Multidisciplinary
Shengnan Wang, Jack Crowther, Hiroyuki Kageshima, Hiroki Hibino, Yoshitaka Taniyasu
Summary: Chemical vapor deposition growth of hBN/graphene bilayers with high-purity moiré phase and interlayer angles under 0.5 degrees has been demonstrated, leading to enhanced carrier mobility. This approach may contribute to the large-scale fabrication of high-quality van der Waals heterostructures.
Article
Nanoscience & Nanotechnology
Tiejun Li, Yaoqi Wang, Ming Yang, Hongliang Hou, Sujun Wu
Summary: High-quality graphene was uniformly dispersed in a copper matrix through chemical vapor deposition, resulting in the formation of a graphene-coated copper powder. Metallurgical bonding between original copper powders was hindered by the graphene during vacuum hot pressing, and copper grains were recrystallized and refined during hot extrusion. Partial agglomeration of graphene during hot extrusion was dispersed again during cold drawing, leading to improved mechanical and electrical properties in the composite.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Chemistry, Multidisciplinary
Saiyu Bu, Yao Chen, Debra J. Searles, Qinghong Yuan
Summary: Crystal domain alignment is crucial for the synthesis of large, single-crystal, two-dimensional materials. However, achieving the alignment has remained unclear. In this study, a physical model and first principles calculations were used to explain the lack of alignment in graphene domains grown on the Cu(111) surface. It was found that small hexagonal graphene domains are always misaligned on the substrate due to preferred binding sites. Only when the domains reach a certain size, near-perfect alignment can be achieved. The results highlight the importance of low nucleation density for epitaxial alignment of graphene domains on Cu(111) surfaces.
MATERIALS TODAY CHEMISTRY
(2023)
Article
Chemistry, Physical
Nilabh Dish, Rakesh Behera, A. Satyaprasad, Abhay Gautam
Summary: This study successfully grows epitaxial Ag, Au, and Cu films on NaCl crystals using a simple approach, and shows a considerable tolerance towards surface misorientation.
APPLIED SURFACE SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Anelia Kakanakova-Georgieva, Ivan G. Ivanov, Nattamon Suwannaharn, Chih-Wei Hsu, Ildiko Cora, Bela Pecz, Filippo Giannazzo, Davide G. Sangiovanni, Gueorgui K. Gueorguiev
Summary: This study investigates the MOCVD process of AlN on epitaxial graphene at temperatures exceeding 1200 degrees C. Epitaxial graphene, in conjunction with high deposition temperatures, facilitates the formation of AlN thin films and maintains material quality. The study also demonstrates the impact of graphene on the dissociation of AlN and GaN precursors.
Article
Chemistry, Multidisciplinary
Ruinan Wu, Yueguo Hu, Peisen Li, Junping Peng, Jiafei Hu, Ming Yang, Dixiang Chen, Yanrui Guo, Qi Zhang, Xiangnan Xie, Jiayu Dai, Weicheng Qiu, Guang Wang, Mengchun Pan
Summary: This study focuses on improving the tunnel magnetoresistance effect in magnetic tunnel junctions by growing high-quality graphene on Ni(111) substrates. Through APCVD, a high-quality graphene/Ni(111) heterostructure with an atomically sharp interface was successfully fabricated, providing a new approach for interface engineering in 2D spintronic applications.
Article
Chemistry, Multidisciplinary
Tobias Huempfner, Felix Otto, Roman Forker, Paul Mueller, Torsten Fritz
Summary: The intercalation of potassium into epitaxial bilayer graphene is shown to enable superconductivity with a critical temperature of Tc = 3.6 +/- 0.1 K. The physical mechanisms are analyzed in detail using scanning tunneling microscopy and angle-resolved photoelectron spectroscopy. The data suggest that electron-phonon coupling is the driving force for superconductivity, and multiple energy gaps are observed. Additionally, the low-dimensional effects lead to a gap ratio exceeding the BCS value for conventional superconductors. These findings highlight the significance of reduced dimensionality in determining the superconducting properties of K-intercalated epitaxial bilayer graphene.
ADVANCED MATERIALS INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Xudong Xue, Xiahong Zhou, Dong Li, Mengya Liu, Shan Liu, Liping Wang, Gui Yu
Summary: A novel approach has been developed to directly prepare twisted bilayer graphene (tBLG) on liquid Cu substrate. The experimental results demonstrate the significant role of liquid Cu substrate and gas flow in the formation of tBLG.
ADVANCED MATERIALS INTERFACES
(2023)
Article
Nanoscience & Nanotechnology
He Zhang, Yang Liu, Jingmei Tao, Yichun Liu, Rui Bao, Fengxian Li, Jianhong Yi
Summary: CNT-GP hybrids are synthesized directly on the surface of Cu powders using Cu as both the catalyst and metal matrix. The resulting sintered composites exhibit a combination of strength and ductility attributed to the interconnected architecture of the chemically hybridized CNT-GP hybrids.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Materials Science, Multidisciplinary
Negar Zebardastan, Jonathan Bradford, Bharati Gupta, Josh Lipton-Duffin, Jennifer MacLeod, Hong Duc Pham, Deepak Dubal, Kostya Ostrikov, Annalena Wolff, Kailong Hu, Yoshikazu Ito, Carlo Mariani, Maria Grazia Betti, Nunzio Motta
Summary: Layered molybdenum disulphide (MoS2) crystals combined with graphene can create diverse 2D heterostructures for tailored applications. By adjusting growth parameters, different structures of MoS2 were successfully developed. MoS2/NPG shows promising electrochemical performance in potassium ion batteries.
ADVANCED MATERIALS TECHNOLOGIES
(2022)
Article
Materials Science, Multidisciplinary
Jinjin Wang, Minsung Kim, Liangyao Chen, Kai-Ming Ho, Michael Tringides, Cai-Zhuang Wang, Songyou Wang
Summary: This paper systematically investigates the effect of lead intercalation on the structural and electronic properties of epitaxial graphene on the SiC substrate. The band structure of Pb-intercalated few-layer graphene can be effectively tuned through intercalation conditions, showing potential for manipulating the electronic properties of graphene layers. Lead intercalation at the interface between the buffer layer and the substrate decouples the layers and can transform the BL into a p-doped graphene layer.
Article
Chemistry, Multidisciplinary
Qinming He, Zhiyuan Tang, Minzhi Dai, Huili Shan, Hui Yang, Yi Zhang, Xin Luo
Summary: Researchers successfully synthesized centimeter-scale 2D ferroelectric In2Se3 films, which exhibit uniform thickness and robust out-of-plane ferroelectricity at room temperature. This finding is of great significance for electronic applications.
Article
Chemistry, Multidisciplinary
Haodong Fan, Menghao Jin, Yongming Luo, Hongxin Yang, Birui Wu, Zhongshu Feng, Yanshan Zhuang, Ziji Shao, Changqiu Yu, Hai Li, Jiahong Wen, Ningning Wang, Bo Liu, Wenjun Li, Tiejun Zhou
Summary: An exchange field gradient is introduced into perpendicularly magnetized synthetic ferro- and antiferromagnets (SFs and SAFs) through the insertion of a slightly wedged Ru between the two layers, enabling field-free switching of perpendicular SFs and SAFs with a high switching ratio. The field-free switching and effective spin-orbit torque (SOT) field are found to depend on the exchange field gradient. The results provide a new approach for achieving field-free switching and high SOT efficiency in perpendicularly magnetized SAFs for advanced magnetic memory devices.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Physics, Multidisciplinary
Zhiwen Wang, Jinghua Liang, Hongxin Yang
Summary: Through first-principles calculations, we find that biaxial strain can effectively manipulate the magnetic parameters of the Janus MnSeTe monolayer, including Heisenberg exchange coupling, Dzyaloshinskii-Moriya interaction, and magnetocrystalline anisotropy. Micromagnetic simulations reveal the distinct phase diagram of chiral spin texture under different strains, demonstrating the inducement of various chiral magnetic structures in the MnSeTe monolayer. The effect of temperature on these magnetic structures is also discussed. The research highlights the Janus MnSeTe monolayer as a promising candidate for spintronic nanodevices.
CHINESE PHYSICS LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Thilini K. Ekanayaka, Okten Ungor, Yuchen Hu, Esha Mishra, Jared P. Phillips, Ashley S. Dale, Saeed Yazdani, Ping Wang, Kayleigh A. McElveen, M. Zaid Zaz, Jian Zhang, Alpha T. N'Diaye, Christoph Klewe, Padraic Shafer, Rebecca Y. Lai, Robert Streubel, Ruihua Cheng, Michael Shatruk, Peter A. Dowben
Summary: Modifications driven by TCNQ affect the spin state configuration and electric conductivity of [Fe(3-bpp)2](TCNQ)2 and [Fe{H2B(pz)2}2(bipy)] and TCNQ mixtures. The addition of TCNQ increases the conductivity and carrier lifetimes of [Fe{H2B(pz)2}2(bipy)]. TCNQ also enhances the transistor carrier mobility of [Fe{H2B(pz)2}2(bipy)] thin films grown using DMF.
MATERIALS CHEMISTRY AND PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Victor Zatko, Regina Galceran, Marta Galbiati, Julian Peiro, Florian Godel, Lisa-Marie Kern, David Perconte, Fatima Ibrahim, Ali Hallal, Mairbek Chshiev, Benjamin Martinez, Carlos Frontera, Lluis Balcells, Piran R. Kidambi, John Robertson, Stephan Hofmann, Sophie Collin, Frederic Petroff, Marie-Blandine Martin, Bruno Dlubak, Pierre Seneor
Summary: 2D materials can be manipulated by proximity effects to modify their electronic structure, allowing for the creation of unique properties in interfaces and heterostructures. In this study, we investigate the possibility of using a ferromagnetic insulator-graphene electrode to design a magnetic tunnel junction. Through the observation of tunnel magnetoresistance, we confirm the emergence of spin polarization in proximitized graphene layers, which is induced by a spin-dependent splitting of the Dirac band structure. This opens up opportunities for utilizing 2D quantum materials in spintronics applications, such as memory cells and logic circuits.
Article
Chemistry, Multidisciplinary
Esha Mishra, Thilini K. Ekanayaka, Theodoros Panagiotakopoulos, Duy Le, Talat S. Rahman, Ping Wang, Kayleigh A. McElveen, Jared P. Phillips, M. Zaid Zaz, Saeed Yazdani, Alpha T. N'Diaye, Rebecca Y. Lai, Robert Streubel, Ruihua Cheng, Michael Shatruk, Peter A. Dowben
Summary: This study investigates the influence of an interface between a semiconducting polyaniline polymer or a polar poly-D-lysine molecular film and valence tautomeric complexes on the electronic structure. X-ray photoemission, X-ray absorption, inverse photoemission, and optical absorption spectroscopy measurements, guided by density functional theory, were used to identify electronic transitions and orbitals. The choice of substrate had little effect on the electronic structure, except for slight modifications in binding energies and orbital levels. A significant ligand-to-metal charge transfer state was observed in the Co-II high-spin state, which was insensitive to the interface between the polymer and tautomeric complexes.
Article
Chemistry, Physical
Thilini Ekanayaka, Tao Jiang, Emilie Delahaye, Olivier Perez, Jean-Pascal Sutter, Duy Le, Alpha T. N'Diaye, Robert Streubel, Talat S. Rahman, Peter A. Dowben
Summary: A chiral 3D coordination compound, [Gd-2(L)(2)(ox)(2)(H2O)(2)], arranged around a dinuclear Gd unit, has been characterized by X-ray photoemission and X-ray absorption measurements. The Gd 5p core level photoemission spectra indicate the dominance of spin orbit coupling over j-J coupling observed in the Gd metal spectra, suggesting the absence of inversion symmetry due to the ligand field. Density functional theory calculations predict antiferromagnetic alignment of the Gd-2 dimers and a band gap consistent with optical absorption.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Physics, Multidisciplinary
Dongxing Yu, Yonglong Ga, Jinghua Liang, Chenglong Jia, Hongxin Yang
Summary: Magnetization switching, an essential operation in spintronic devices, is usually achieved by spin-transfer torque or spin-orbit torque. However, these techniques require current and can cause Joule heating. This study introduces an alternative mechanism called Dzyaloshinskii-Moriya interaction torque, which allows for magnetization switching controlled by voltage pulses, offering potential for magnetic-field-free and current-free spintronic devices and neuromorphic computing.
PHYSICAL REVIEW LETTERS
(2023)
Review
Physics, Multidisciplinary
Qirui Cui, Liming Wang, Yingmei Zhu, Jinghua Liang, Hongxin Yang
Summary: In this review, the authors comprehensively survey three types of basic terms related to spin interactions in 2D magnets: magnetic anisotropy, exchange coupling, and Dzyaloshinskii-Moriya interaction (DMI). The physical features and origins of these terms are introduced, along with many correlated phenomena, which are significant for the advancement of 2D spintronics.
FRONTIERS OF PHYSICS
(2023)
Article
Nanoscience & Nanotechnology
Yingmei Zhu, Qirui Cui, Hongxin Yang
Summary: Using model analysis and first-principles calculations, it is shown that the intrinsic ferromagnetic field of materials can effectively modulate the non-Dirac band dispersions. The four-bands kp model demonstrates the lifting of band dispersion degeneracy at the & UGamma; point when magnetization rotates from in-plane to out-of-plane. The spin components of the lower or upper two bands tend to become identical with the enhancement of the exchange field, resulting in non-trivial topology.
Article
Physics, Condensed Matter
Peng Li, Yonglong Ga, Qirui Cui, Jinghua Liang, Dongxing Yu, Hongxin Yang
Summary: Based on first-principles calculations, this study investigates the effect of hole doping on the ferromagnetism and Dzyaloshinskii-Moriya interaction (DMI) in PbSnO2, SnO2, and GeO2 monolayers. The transition from nonmagnetic to ferromagnetic and the emergence of DMI can occur simultaneously in these two-dimensional IVA oxides. Increasing the hole doping concentration strengthens the ferromagnetism in all three oxides. Different inversion symmetry breaking leads to isotropic DMI in PbSnO2 and anisotropic DMI in SnO2 and GeO2. Moreover, topological spin textures can be induced in PbSnO2 through DMI with varying hole concentrations, and antiskyrmions or antibimerons can be found in SnO2 and GeO2 with different hole concentrations. These findings demonstrate the presence and tunability of topological chiral structures in p-type magnets, providing new possibilities for spintronics.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2023)
Article
Materials Science, Multidisciplinary
Quentin Guillet, Libor Vojacek, Djordje Dosenovic, Fatima Ibrahim, Herve Boukari, Jing Li, Fadi Choueikani, Philippe Ohresser, Abdelkarim Ouerghi, Florie Mesple, Vincent Renard, Jean-Francois Jacquot, Denis Jalabert, Hanako Okuno, Mairbek Chshiev, Celine Vergnaud, Frederic Bonell, Alain Marty, Matthieu Jamet
Summary: In this study, five-monolayer quasifreestanding Cr2Te3 films were successfully grown on three classes of 2D materials (graphene, WSe2, and Bi2Te3) using molecular beam epitaxy. The films exhibited strong magnetism and high Curie temperature, with sharp van der Waals interfaces. The strength of the magnetism was found to be tunable by strain.
PHYSICAL REVIEW MATERIALS
(2023)
Article
Physics, Multidisciplinary
Albert Fert, Mairbek Chshiev, Andre Thiaville, Hongxin Yang
Summary: Since the early 1960's, the discovery of Dzyaloshinskii-Moriya interaction (DMI) has explained various magnetic phenomena and gained increasing interest for its role in stabilizing magnetic domain walls and magnetic skyrmions. DMI is governed by spin-orbit coupling (SOC) and inversion symmetry breaking (ISB), leading to distinct morphologies of magnetic skyrmions. This research aims to introduce the history of DMI and its significance in the field of modern spintronics.
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN
(2023)
Article
Materials Science, Multidisciplinary
Qirui Cui, Yingmei Zhu, Jinghua Liang, Ping Cui, Hongxin Yang
Summary: In this study, the researchers propose and demonstrate that a variety of AFM topological spin textures can be induced in van der Waals synthetic antiferromagnets, such as MnBi2Se(S)2Te2 bilayer and trilayer. These noncollinear spin textures are closely related to stacking properties and possess unique spin dynamics.
Article
Materials Science, Multidisciplinary
Peng Li, Dongxing Yu, Jinghua Liang, Yonglong Ga, Hongxin Yang
Summary: The search for topological magnetism in 2D magnetic materials is a hot topic in spintronics. This study presents comprehensive investigations of magnetic phases in a series of Janus monolayers (MnXZ and CrYZ) using first-principles calculations and atomistic spin model simulations. Notably, sizable Dzyaloshinskii-Moriya interaction is observed in these monolayers due to the breaking of inversion symmetry. Furthermore, the monolayers exhibit different degrees of magnetic frustration and isotropic higher-order interactions. Atomistic spin model simulations reveal the generation of various topological spin textures through complex magnetic interactions. These findings offer valuable insights and fundamental understanding for the field of topological magnetism in 2D materials.
Review
Physics, Applied
Hongxin Yang, Jinghua Liang, Qirui Cui
Summary: Understanding magnetic interactions is fundamental in condensed-matter physics and spintronic device applications. The Dzyaloshinskii-Moriya interaction (DMI) has attracted increasing attention for its ability to trigger topological chiral magnetism. First-principles calculations have played a crucial role in revealing the microscopic properties of DMI and searching for materials with strong DMI.
NATURE REVIEWS PHYSICS
(2023)
