Article
Optics
Chenni Xu, Li-Gang Wang, Patrick Sebbah
Summary: An approach to undo chaotic behavior and control ray trajectories in optical billiards is presented. By introducing spatially varying refractive index using conformal mapping, the chaotic billiard system becomes fully predictable and integrable. Additionally, the connection between chaotic billiards and non-Euclidean geometries allows for the manipulation of trajectories. This method opens up potential applications in the field of optical microcavities.
LASER & PHOTONICS REVIEWS
(2023)
Review
Chemistry, Multidisciplinary
Hu Qiu, Wanqi Zhou, Wanlin Guo
Summary: Nanopore techniques using 2D materials offer a cost-effective, label-free, high-throughput platform for single-molecule biosensing and DNA sequencing. These materials have the potential to provide the highest possible spatial resolution and extend the technical capabilities of traditional nanopore devices. However, challenges such as reducing noise levels, slowing down DNA translocation, and inhibiting DNA fluctuations inside pores need to be addressed for the development of effective 2D material nanopores for DNA sequencing.
Article
Chemistry, Physical
Luiz G. Pimenta Martins, Diego L. Silva, Jesse S. Smith, Ang-Yu Lu, Cong Su, Marek Hempel, Connor Occhialini, Xiang Ji, Ricardo Pablo, Rafael S. Alencar, Alan C. R. Souza, Alysson A. Pinto, Alan B. de Oliveira, Ronaldo J. C. Batista, Tomas Palacios, Mario S. C. Mazzoni, Matheus J. S. Matos, Riccardo Comin, Jing Kong, Luiz G. Cancado
Summary: Researchers successfully compressed few-layer graphene samples in water to form a hard, transparent, sp(3)-containing 2D phase. Raman spectroscopy data showed a similar critical pressure for the new phase and graphene/graphite, as well as a lack of evidence of significant pressure gradients or non-hydrostatic stress components.
Article
Engineering, Environmental
Xuanhao Wu, Kali Rigby, Dahong Huang, Tayler Hedtke, Xiaoxiong Wang, Myoung Won Chung, Seunghyun Weon, Eli Stavitski, Jae-Hong Kim
Summary: A new graphene oxide-based membrane architecture was developed to efficiently degrade a specific pollutant using cobalt catalysts loaded in nanoscale pore walls. The use of a unique synthesis procedure enabled the dispersion of cobalt atoms uniformly, maintaining the membrane's structure and functionality. This study presents a critical advancement in developing catalytic membranes that combine membrane filtration and advanced oxidation processes in a more efficient single-step treatment.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2022)
Article
Chemistry, Multidisciplinary
Ziying Li, Shuilin Li, Yongjie Xu, Nujiang Tang
Summary: Graphene is regarded as a promising material for spintronic applications due to its remarkable electrical properties. Many theoretical and experimental studies have shown the feasibility and significance of inducing magnetism in graphene-based systems. This review provides an overview of the latest developments in graphene's magnetism over the past five years, considering its dimensional aspects, including nanoflakes (0D), graphene nanoribbons (1D), graphene sheets, and twisted bilayer graphene (2D). Various methods, such as edge engineering, defect engineering, sp(3) functionalization, heteroatom adsorption, and interlayer rotation, are proposed to induce intriguing magnetic behaviors. Lastly, the challenges and opportunities in the field are summarized to guide future research.
CHEMICAL COMMUNICATIONS
(2023)
Article
Optics
Chenglong Wang, Xiang Guo, Xidong Wu
Summary: This paper proposes and investigates a graphene plasmonic lens with an electrically tunable focal length. By controlling the gate voltage of graphene, the lens can be continuously tuned from a Maxwell Fisheye lens to a Luneburg lens, and excellent focusing performances are achieved.
Article
Materials Science, Ceramics
Dheeraj Kumar Gara, Gujjala Raghavendra, P. Syam Prasad, S. Ojha
Summary: The research found that reduced functional group density graphene has good adhesion and enhancement effects in composite materials, making it suitable for structural applications in aerospace industry.
CERAMICS INTERNATIONAL
(2021)
Article
Physics, Multidisciplinary
Rafael M. Fernandes, Liang Fu
Summary: Unconventional nematic superconductors in lattices with specific rotational symmetries may support a charge-4e superconducting phase, due to a hidden discrete symmetry in the Ginzburg-Landau theory. Random strain may favor the charge-4e state over the nematic phase in two-dimensional inhomogeneous systems displaying nematic superconductivity.
PHYSICAL REVIEW LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Guangqi Zhu, Yanling Qi, Fan Liu, Shenqian Ma, Guolei Xiang, Fengmin Jin, Zigeng Liu, Wei Wang
Summary: The ordinary intrinsic activity and disordered distribution of metal sites in zero/one-dimensional single-atom catalysts lead to inferior catalytic efficiency and short-term endurance in the oxygen reduction reaction, restricting their large-scale application in hydrogen-oxygen fuel cells and metal-air batteries. By conjugating 1D Fe SACs with 2D graphene film to form a composite structure with well-ordered atomic-Fe coordination, the Fe SAC@G product exhibits outstanding ORR electrocatalytic efficiency and stability. DFT-D computational results suggest that the intrinsic ORR activity of Fe SAC@G originates from the newly-formed FeN4-O-FeN4 bridge structure with moderate adsorption ability towards ORR intermediates.
Article
Multidisciplinary Sciences
Seo Woo Song, Sumin Lee, Jun Kyu Choe, Na-Hyang Kim, Junwon Kang, Amos Chungwon Lee, Yeongjae Choi, Ahyoun Choi, Yunjin Jeong, Wooseok Lee, Ju-Young Kim, Sunghoon Kwon, Jiyun Kim
Summary: This technology utilizes surface tension-driven capillary peeling and floating of dried ink film to transform pen-drawn 2D structures into 3D structures, with selective control of floating and anchoring parts facilitating the transformation. Structural reinforcement using surface-initiated polymerization allows for fixation of the transformed 3D geometry.
Article
Multidisciplinary Sciences
Li-Yun Tian, Oliver Gutfleisch, Olle Eriksson, Levente Vitos
Summary: This study examines the effect of alloying FeNi with other elements on its phase formation and ordering properties, finding that the addition of small amounts of elements can increase the order-disorder transition temperature, and demonstrates that alloying is an effective method for stabilizing the ordered tetragonal phase of FeNi.
SCIENTIFIC REPORTS
(2021)
Article
Chemistry, Multidisciplinary
Justin C. Ondry, Layne B. Frechette, Phillip L. Geissler, A. Paul Alivisatos
Summary: The goal of this work is to identify factors that affect structural order in 2D self-assembled superlattices of polygon-shaped colloidal nanocrystals. Experimental and simulation results show that cube-shaped nanocrystals have less translational order compared to hexagonal prism-shaped nanocrystals. This difference is attributed to the geometric considerations inherent to different polygonal shapes and their superlattices. Cube assemblies have a narrower orientation distribution due to their simpler shape compared to hexagonal prisms.
Article
Chemistry, Multidisciplinary
Z. Yang, M. Xiang, Z. Wu, W. Fan, J. Hui, C. Yu, S. Dong, H. Qin
Summary: In this study, a rare-earth lanthanum (La) was introduced into N-doped graphene oxide (NGO) to form the single-atom 2D La@NGO, which exhibited excellent oxygen reduction reaction performances and methanol tolerance. The 7%La@NGO showed the best performance among the La@NGO series, surpassing the commercial Pt/C electrocatalyst, and also exhibited good bifunctional electrocatalytic behaviors. The rechargeable zinc-air battery assembled with 7%La@NGO demonstrated high power density, large specific capacity, high rechargeable efficiency, and excellent cycling stability.
MATERIALS TODAY CHEMISTRY
(2022)
Article
Physics, Multidisciplinary
Benjamin Verlhac, Lorena Niggli, Anders Bergman, Umut Kamber, Andrey Bagrov, Diana Iusan, Lars Nordstrom, Mikhail Katsnelson, Daniel Wegner, Olle Eriksson, Alexander A. Khajetoorians
Summary: This study presents an unusual magnetic transition in neodymium, where long-range multi-Q magnetic order emerges from a self-induced spin glass with increasing temperature. The local order of the spin glass phase is characterized using temperature-dependent spin-polarized scanning tunnelling microscopy, and the emergence of long-range multi-Q order is quantified. Analysis tools are developed to determine the glass transition temperature from measurements of spatially dependent magnetization. Atomistic spin dynamics simulations reproduce the observed phase transition and trace the origin of the high-temperature order. These findings demonstrate an example of order from disorder and provide a platform for studying the magnetization dynamics of a self-induced spin glass.
Article
Nanoscience & Nanotechnology
Shuai Zhou, Jing Bai, Tiantian Li, Xiaxin Gao, Ruoyu Xu, Zixing Shi
Summary: Inspired by the elongation ability of cells on mimosa petiole, we have developed a shape transformation polymer that can switch between 2D and 3D at room temperature through simple stretching and releasing steps. By patterning the surface of the sample film, we induced different movements of the polymer chains along the thickness, resulting in shape transformation. This research expands the application of shape memory polymers and shows potential in information encryption transmission.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Materials Science, Multidisciplinary
Lingxiu Chen, Kenan Elibol, Haifang Cai, Chengxin Jiang, Wenhao Shi, Chen Chen, Hui Shan Wang, Xiujun Wang, Xiaojing Mu, Chen Li, Kenji Watanabe, Takashi Taniguchi, Yufeng Guo, Jannik C. Meyer, Haomin Wang
Summary: The study investigates the stacking order and wrinkles of h-BN using transmission electron microscopy, confirming that the layers in h-BN flakes are arranged in the AA' stacking. The wrinkles, forming a threefold network throughout the crystal, are oriented along the armchair direction.
Article
Physics, Applied
Stefan Hummel, Kenan Elibol, Dengsong Zhang, Krishna Sampathkumar, Otakar Frank, Dominik Eder, Christian Schwalb, Jani Kotakoski, Jannik C. Meyer, Bernhard C. Bayer
Summary: Suspended 2D membranes are important for various applications, but characterization with scanning probe microscopy techniques can be affected by deformations during measurements. By coupling AFM with SEM, researchers can directly visualize and study the deformations of 2D membranes induced by controlled AFM manipulations, providing a new approach for research.
APPLIED PHYSICS LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Alberto Trentino, Jacob Madsen, Andreas Mittelberger, Clemens Mangler, Toma Susi, Kimmo Mustonen, Jani Kotakoski
Summary: By utilizing a near ultrahigh vacuum system and advanced imaging techniques, researchers have overcome various difficulties in the structural engineering of 2D materials, successfully preparing and fully characterizing atomically clean free-standing graphene with controlled defect distribution.
Article
Chemistry, Multidisciplinary
Jonas Haas, Finn Ulrich, Christoph Hofer, Xiao Wang, Kai Braun, Jannik C. Meyer
Summary: Researchers have successfully stacked individual layers of two-dimensional materials using van der Waals interaction and modified them using electron irradiation and etching techniques to achieve precise control and assembly of structures. The process allows for accurate alignment and stacking of layers under electron microscopy, enabling the fabrication of almost any three-dimensional structure with high spatial resolution.
Article
Chemistry, Multidisciplinary
Kimmo Mustonen, Christoph Hofer, Peter Kotrusz, Alexander Markevich, Martin Hulman, Clemens Mangler, Toma Susi, Timothy J. Pennycook, Karol Hricovini, Christine Richter, Jannik C. Meyer, Jani Kotakoski, Viera Skakalova
Summary: Researchers have successfully stabilized a 2D structure composed of copper and iodine at room temperature by using graphene oxide as the template material, providing a new method for producing more exotic phases of materials for experiments.
ADVANCED MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Alberto Trentino, Kenichiro Mizohata, Georg Zagler, Manuel Laengle, Kimmo Mustonen, Toma Susi, Jani Kotakoski, E. Harriet Ahlgren
Summary: This study demonstrates an efficient method to implant individual gold atoms into graphene, with the ability to control the concentration of gold atoms introduced. Covalently bound gold atoms in graphene can withstand high-intensity electron irradiation during microscopy experiments.
Article
Materials Science, Multidisciplinary
Georg Zagler, Maximilian Stecher, Alberto Trentino, Fabian Kraft, Cong Su, Andreas Postl, Manuel Laengle, Christian Pesenhofer, Clemens Mangler, E. Harriet Ahlgren, Alexander Markevich, Alex Zettl, Jani Kotakoski, Toma Susi, Kimmo Mustonen
Summary: Substituting heteroatoms into graphene can tune its properties for various applications. Recent discovery shows that covalent impurities in graphene can be manipulated at atomic precision. This study reports the vacancy-mediated substitution of aluminium into laser-cleaned graphene and investigates their dynamics under electron irradiation. The results show good agreement with predictions and reveal interesting findings.
Article
Chemistry, Physical
Andreas Postl, Pit Pascal Patrick Hilgert, Alexander Markevich, Jacob Madsen, Kimmo Mustonen, Jani Kotakoski, Toma Susi
Summary: We estimated the migration barrier of carbon adatoms on freestanding monolayer graphene to be (0.33 ± 0.03) eV by quantifying its temperature-dependent electron knock-on damage.
Article
Physics, Multidisciplinary
Anna Niggas, Janine Schwestka, Karsten Balzer, David Weichselbaum, Niclas Schluenzen, Rene Heller, Sascha Creutzburg, Heena Inani, Mukesh Tripathi, Carsten Speckmann, Niall McEvoy, Toma Susi, Jani Kotakoski, Ziyang Gan, Antony George, Andrey Turchanin, Michael Bonitz, Friedrich Aumayr, Richard A. Wilhelm
Summary: We compared the ion-induced electron emission from freestanding monolayers of graphene and MoS2 and found that graphene emitted six times more electrons, despite both materials having similar work functions. This can be explained by a charge-up in MoS2 that prevents low energy electrons from escaping the surface within a few femtoseconds after ion impact.
PHYSICAL REVIEW LETTERS
(2022)
Article
Chemistry, Multidisciplinary
E. Harriet Ahlgren, Alexander Markevich, Sophie Scharinger, Bernhard Fickl, Georg Zagler, Felix Herterich, Niall McEvoy, Clemens Mangler, Jani Kotakoski
Summary: Oxidation is the main cause of degradation in 2D materials, especially transition metal dichalcogenides (TMDs). This study investigates the chemical effects of oxygen on single-layer MoS2 and MoTe2 under controlled low-pressure oxygen environments using in situ electron microscopy. It is found that MoTe2 is reactive to oxygen and undergoes significant degradation, while MoS2 is inert. Additionally, hydrocarbon contamination accelerates the degradation rate of TMDs. The findings provide important insights into the oxygen-related deterioration of 2D materials.
ADVANCED MATERIALS INTERFACES
(2022)
Article
Chemistry, Multidisciplinary
Rajendra Singh, Daniel Scheinecker, Ursula Ludacka, Jani Kotakoski
Summary: Graphene, the best known 2D material, is prone to corrugations. Factors such as the size of the free-standing area, preparation method, surface contamination, and electron-beam-induced disorder affect the corrugation in graphene.
Article
Nanoscience & Nanotechnology
Kenan Elibol, Toma Susi, Clemens Mangler, Dominik Eder, Jannik C. Meyer, Jani Kotakoski, Richard G. Hobbs, Peter A. van Aken, Bernhard C. Bayer
Summary: The presence of metal atoms at the edges of graphene nanoribbons (GNRs) allows for tailoring their physical properties. In this study, indium (In) chains were formed on the edges of graphene-supported GNRs through laser heating and physical vapor deposition. Aberration-corrected scanning transmission electron microscopy (STEM) revealed that multiple In atoms preferred to decorate the edges of the GNRs. Electron-beam irradiation induced the migration of In atoms along the edges and the formation of longer chains. Theoretical calculations confirmed the metallic character of these structures. This research provides insights into the formation and properties of long linear metal atom chains at graphitic edges.
NPJ 2D MATERIALS AND APPLICATIONS
(2023)
Article
Materials Science, Multidisciplinary
Alexandru Chirita, Alexander Markevich, Mukesh Tripathi, Nicholas A. Pike, Matthieu J. Verstraete, Jani Kotakoski, Toma Susi
Summary: This study presents a comprehensive three-dimensional first-principles theory of knock-on displacements in materials, describing the dynamics of irradiation-induced damage. The model is validated using precise measurements of knock-on damage in graphene, and is applied to study reversible jumps of pyridinic nitrogen atoms. The results indicate stronger inelastic effects at defects compared to pristine graphene.