Article
Chemistry, Physical
Shijie Sun, Baijin Li, Wei Xiong, Boyu Fu, Yong Zhang, Zilin Ruan, Lei Gao, Xiaoqing Zuo, Jianchen Lu, Jinming Cai
Summary: Supramolecular self-assembly is a feasible approach for nanopatterning and functionality, and selective adsorption at the molecular scale is crucial for both fundamental and practical applications. A controllable method for fabricating distorted Kagome-like networks by coupling molecular functional groups and substrate atoms was demonstrated. A chiral Kagome-like network was constructed using precursor molecules and scanning tunneling microscopy combined with density functional theory was used to examine the assembly mechanisms and cavity characteristics. The efficient template properties of Kagome-like networks for regulating the adsorption configuration of C60 were also explored.
APPLIED SURFACE SCIENCE
(2023)
Article
Chemistry, Physical
Ping Zhang, Linjie Chen, Shaoxiang Sheng, Wenqi Hu, Huiru Liu, Chen Ma, Zijia Liu, Baojie Feng, Peng Cheng, Yiqi Zhang, Lan Chen, Jin Zhao, Kehui Wu
Summary: This study investigated the adsorption and self-assembly structures of melamine molecules on an Ag(111) surface using low temperature scanning tunneling microscopy (STM) combined with tip-enhanced Raman spectroscopy (TERS). Two ordered self-assembly phases of melamine molecules on Ag(111) were observed, and it was found that the dehydrogenation of melamine can be controlled by annealing the sample or through a tip-enhanced photo-catalytic effect.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Pin-Chiao Huang, Hongye Sun, Mamun Sarker, Christopher M. Caroff, Gregory S. Girolami, Alexander Sinitskii, Joseph W. Lyding
Summary: This paper demonstrates the fabrication of nanometer-scale metal contacts on individual graphene nanoribbons (GNRs) and the use of these contacts to control the electronic character of the GNRs. Using a low-voltage direct-write STM-based process, sub-5 nm metallic hafnium diboride (HfB2) contacts are patterned directly on top of single GNRs in an ultrahigh-vacuum scanning tunneling microscope (UHV-STM), with all the fabrication performed on a technologically relevant semiconductor silicon substrate. Scanning tunneling spectroscopy (STS) data verify the expected metallic and semiconducting character of the contacts and GNR, and also show induced band bending and p-n junction formation in the GNR due to the metal-GNR work function difference. Contact engineering with different work function metals eliminates the need for complex chemical doping to create GNRs with different characteristics. This paper demonstrates the successful fabrication of precise metal contacts and local p-n junction formation on single GNRs.
Article
Chemistry, Multidisciplinary
Viliam Vano, Somesh Chandra Ganguli, Mohammad Amini, Linghao Yan, Maryam Khosravian, Guangze Chen, Shawulienu Kezilebieke, Jose L. Lado, Peter Liljeroth
Summary: Unconventional superconductors, particularly nodal superconductors, have been a focus in modern quantum materials research. This study demonstrates the existence of nodal superconductivity in pristine monolayer 1H-TaS2 using low-temperature scanning tunneling microscopy (STM) and spectroscopy (STS) experiments. It is also found that non-magnetic disorder can drive the nodal state to a conventional gapped s-wave state, and many-body excitations emerge near the gap edge, indicating a potential unconventional pairing mechanism.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Lukas Grossmann, Eva Ringel, Atena Rastgoo-Lahrood, Benjamin T. King, Johanna Rosen, Wolfgang M. Heckl, Dorina Opris, Jonas Bjoerk, Markus Lackinger
Summary: Currently, there is limited research on the self-assembly of three-dimensional molecules on surfaces. These molecules have a greater variability in their modes of adsorption compared to (nearly) planar molecules. This variability can significantly affect the expression of intermolecular binding motifs and the formation of supramolecular structures. The study found that molecule-surface interactions can be tuned to facilitate crystal engineering in two dimensions.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Yi-Ying Sung, Harmina Vejayan, Christopher J. Baddeley, Neville V. Richardson, Federico Grillo, Renald Schaub
Summary: On-surface synthesis with designer precursor molecules is an effective method for preparing graphene nanoribbons (GNRs) with tunable electronic properties. The band gap of GNRs doped with heteroatoms remains unchanged, but hydrogenation can engineer a tunable band gap. Surface-confined hydrogenation studies on 7-armchair GNRs grown on Au(111) surfaces reveal a self-limited hydrogenation process. The electronic properties of the GNR/Au(111) system can be modified by edge and basal-plane hydrogenation, and a mechanism for the hydrogenation process is proposed.
Review
Polymer Science
Zhi Li, Yanan Li, Chengjie Yin
Summary: This article discusses the phenomenon of ordered self-assembly on solid substrates, and its importance in both fundamental surface science research and its applications in nanotechnology. By utilizing scanning tunneling microscopy (STM), researchers can investigate the structural transition of self-assembled molecules and provide advanced methods for controlling and regulating self-assembly structures.
Article
Chemistry, Multidisciplinary
Tobias Weiss, Aleksandr Baklanov, Georg S. Michelitsch, Karsten Reuter, Martin Schwarz, Manuela Garnica, Willi Auwarter
Summary: This study presents the first real space characterization of borazine molecules and their self-assemblies on solid supports. The adsorption of borazine on Ag(111) surface is weak and non-dissociative, with the ring aligned parallel to the surface plane. Borazine molecules prefer hollow adsorption sites, leading to the assembly of both porous and dense-packed structures. STM-based manipulation is demonstrated to modify the borazine adsorption configuration.
ADVANCED MATERIALS INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Chi Ming Yim, Soumendra Nath Panja, Christopher Trainer, Craig Topping, Christoph Heil, Alexandra S. Gibbs, Oxana Magdysyuk, Vladimir Tsurkan, Alois Loidl, Andreas W. Rost, Peter Wahl
Summary: The passage discusses the tuning of the ground state of the nonsuperconducting parent compound, Fe1+xTe, of the iron chalcogenides by uniaxial strain, highlighting the peculiar (pi, 0) antiferromagnetic order exhibited by iron telluride. The study demonstrates a transition to a (pi, pi)-charge-ordered state on the surface of Fe1.1Te under strain, showcasing the opportunities offered by 2D correlated phases near surfaces and interfaces.
Article
Chemistry, Multidisciplinary
Stefania Moro, Nicholas Siemons, Oscar Drury, Daniel A. Warr, Thomas A. Moriarty, Luis M. A. Perdigao, Drew Pearce, Maximilian Moser, Rawad K. . Hallani, Joseph Parker, Iain McCulloch, Jarvist M. Frost, Jenny Nelson, Giovanni Costantini
Summary: Conjugated polymers with glycol-based chains have promising applications in bioelectronics and thermoelectrics. In this study, we determined the microstructure of these polymers with submonomer resolution and found that the side chains play a crucial role in polymer assembly. The conformation of the side chains is influenced by their free analogues, rather than the backbone torsional potential energy. These findings can be extended to other conjugated polymers for microstructure characterization.
Article
Chemistry, Physical
Karsten Lucht, Karina Morgenstern
Summary: The study reveals that functionalized azobenzene molecules form water-azobenzene complexes in the presence of water, which prefer linear arrangements mediated by functionalized end groups. These complexes can serve as model systems for investigating the influence of a solvent on surface reactions.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Xin Tan, Jinliang Pan, Yangfan Wu, Peng Xu, Luye Sun, Kui Hu, Xia Qiu, Menglei Li, Mengxi Liu, Donglin Ma, Xiaohui Qiu
Summary: In this study, the formation of stable Na3Cl nanoclusters and a Na3Cl4 monolayer was directly observed using scanning tunneling microscopy and non-contact atomic force microscopy. The stability of these structures was confirmed through density functional theory calculations. The study also found that charge transfer between the nanoclusters and the metal substrate stabilized NaCl of non-1:1 stoichiometry.
Article
Chemistry, Multidisciplinary
Shanchao Tan, Wendi Luo, Yongjie Zhang, Xiang-Kui Ren, Yuhong Liu, Zhijian Chen, Qingdao Zeng
Summary: The self-assembly process of a BODIPY derivative functionalized with uracil groups was thoroughly investigated using STM and DFT methods. The formation of hydrogen bonds between uracil groups was identified as the key factor contributing to the construction of ordered self-assembly structure. Additionally, the nanotribological property of the self-assembly on HOPG surface was measured using AFM.
FRONTIERS IN CHEMISTRY
(2021)
Article
Multidisciplinary Sciences
Alexander Kerelsky, Carmen Rubio-Verdu, Lede Xian, Dante M. Kennes, Dorri Halbertal, Nathan Finney, Larry Song, Simon Turkel, Lei Wang, Kenji Watanabe, Takashi Taniguchi, James Hone, Cory Dean, Dmitri N. Basov, Angel Rubio, Abhay N. Pasupathy
Summary: This study demonstrates the formation of emergent correlated phases in multilayer rhombohedral graphene without the need for twisted van der Waals layers. The study shows that two layers of bilayer graphene twisted by a tiny angle can host large regions of uniform rhombohedral four-layer graphene with a sharp van Hove singularity. Furthermore, the study suggests that the broken symmetry state in ABCA graphene could be attributed to a charge-transfer excitonic insulator or a ferrimagnet.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Chemistry, Multidisciplinary
Keda Jin, Tobias Wichmann, Sabine Wenzel, Tomas Samuely, Oleksander Onufriienko, Pavol Szabo, Kenji Watanabe, Takashi Taniguchi, Jiaqiang Yan, F. Stefan Tautz, Felix Luepke, Markus Ternes, Jose Martinez-Castro
Summary: This paper reports a dry polymer-based assembly technique for fabricating atomically clean surfaces in van der Waals heterostructures. The technique avoids contact between polymers and the heterostructure surface, is solvent-free, can be performed in a glovebox, and only requires temperatures below 130 degrees C. The fabricated heterostructures demonstrate ultra-clean interfaces and surfaces, making this technique potentially compatible with assembly under ultra-high vacuum conditions for ultimate heterostructure quality.
ADVANCED MATERIALS INTERFACES
(2023)
Article
Materials Science, Multidisciplinary
J. Ledieu, M. Feuerbacher, C. Thomas, M-C de Weerd, S. Sturm, M. Podlogar, J. Ghanbaja, S. Migot, M. Sicot, V Fournee
Summary: The study focused on the (110) and (320) surfaces of single-phase FeCrMnNiCo solid solution, finding a clear surface co-segregation of Mn and Ni. At high temperatures, Mn desorbs while the Ni content increases linearly. Different surface morphologies and structures were observed using low energy electron diffraction and scanning tunneling microscopy.
Article
Chemistry, Physical
L. Boulley, D. Kandaskalov, M-C de Weerd, S. Migot, J. Ghanbaja, S. Sturm, P. Boulet, J. Ledieu, E. Gaudry, V Fournee
Summary: The bulk structure of the eta-Al5Fe2 intermetallic compound consists of a framework of pentagonal antiprims with nearly continuous chains of fractionally occupied Al sites. Surface investigation of this compound has not been reported yet, despite its technological importance, and the growth of a single crystal of this compound by the Czochralski method is described in this study. Density Functional Theory calculations were performed to determine its formation enthalpy and electronic structure, showing a deep pseudogap at the Fermi energy and the compound's magnetic nature.
APPLIED SURFACE SCIENCE
(2021)
Article
Chemistry, Physical
E. Gaudry, J. Ledieu, V. Fournee
Summary: Nanostructured alloy surfaces have unique physical properties and chemical reactivities that can benefit the design of catalysts and electronic devices. The cluster-based bulk structure offers an alternative method for building surfaces with specific morphologies, relying on specific electronic structures and experimental conditions. The study explores the surface structures of cluster-based intermetallics and how they impact the growth of atomic and molecular thin films.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
P. Kozelj, S. Vrtnik, M. Krnel, A. Jelen, D. Gacnik, M. Wencka, Z. Jaglicic, A. Meden, G. Drazic, F. Danoix, J. Ledieu, M. Feuerbacher, J. Dolinsek
Summary: The CoCrFeMnNi high-entropy alloy is a highly crystalline system with magnetic lattice sites, showing randomness and frustration. It undergoes a kinetic freezing transition to a spin glass phase at lower temperatures, where the system's ergodicity is broken. This non-equilibrium dynamic behavior is associated with transient effects of partial equilibration within localized spin domains.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2021)
Article
Materials Science, Coatings & Films
A. K. Shukla, J. Ledieu, E. Gaudry, D. M. Wu, T. A. Lograsso, V. Fournee
Summary: In this study, the growth and electronic structure of Ag thin films on the fivefold surface of the icosahedral (i)-Al-Cu-Fe quasicrystal were investigated using various characterization techniques. The experiments revealed the formation of crystalline structures in Ag thin films at specific coverages, and the observation of quantum well states in the photoemission spectra confirmed the electronic growth of Ag thin films on quasicrystalline surfaces.
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A
(2022)
Article
Chemistry, Physical
C. Ruano Merchan, T. T. Dorini, F. Brix, L. Pasquier, M. Jullien, D. Pierre, S. Andrieu, K. Dumesnil, S. S. Parapari, S. Sturm, J. Ledieu, M. Sicot, O. Copie, E. Gaudry, V Fournee
Summary: This study investigated the formation of new complex phases in thin films deposited on Al2O3(0001) substrate by pulsed laser deposition followed by high temperature annealing. The discovered phases include a large square approximant and a 2D hexagonal approximant, both constructed from similar basic tiles. The research also revealed differences in electronic structure and adhesion properties of the two approximants, suggesting unique chemical and physical characteristics.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Chemistry, Inorganic & Nuclear
Pascal Boulet, Marie-Cecile de Weerd, Emilie Gaudry, Saso Sturm, Julien Zollinger, Jean-Marie Dubois, Vincent Fournee, Julian Ledieu
Summary: A binary phase with Al4Ir composition has been discovered in the Al-Ir binary system. Its crystal structure and metastable nature have been characterized by various techniques, including X-ray diffraction, scanning transmission electron microscopy, and differential thermal analysis measurements.
INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Physical
D. Dubaux, F. Brix, E. Gaudry, P. Gille, M-C de Weerd, V Fournee, M. Sicot, J. Ledieu
Summary: We investigated the formation of complex intermetallics as surface alloys upon the adsorption of Fe on Al9Co(001). Different dosing conditions and measurement methods were used to identify several phases, including a high-temperature phase and two different phases. The structure and stability of these phases were characterized through experiments and calculations.
APPLIED SURFACE SCIENCE
(2022)
Article
Chemistry, Physical
Joseph A. Smerdon, Vincent Fournee, Julian Ledieu, Katariina Pussi
Summary: In this study, carbon-60 molecules were deposited on the fcc Ni(111) surface and the surface of bulk hcp Co(0001) for the first time, and were measured using low-energy electron diffraction and scanning tunneling microscopy. The formation of an adlayer with predominantly (4 x 4) domains was observed in both cases, with other domains representing chiral epitaxial degeneracy. Annealing resulted in the formation of films with bright and dim molecules, with differences depending on the substrate. For C60 adsorption atop Ni(111), annealing led to the formation of vacancies beneath dim molecules and adatom nucleation below bright molecules.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Physical
Lhonidas de Senna Junior, Alexandre Pancotti, Alex Sandre Kilian, Abner de Siervo, Renee D. D. Diehl, Marie-Cecile de Weerd, Julian Ledieu, Emilie Gaudry, Vincent Fournee, Guilherme Jean P. Abreu
Summary: In this study, the single crystal of Al5Co2(001) was characterized by XPS, LEED, and PED, and the crystal structure was analyzed using LEED patterns. The best termination was found to be the Al-rich surface layer.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Nanoscience & Nanotechnology
Corentin Chatelier, Kanika Anand, Peter Gille, Marie-Cecile De Weerd, Julian Ledieu, Vincent Fournee, Andrea Resta, Alina Vlad, Yves Garreau, Alessandro Coati, Emilie Gaudry
Summary: Hot-dip coating with low weight aluminum metal can enhance the performance of steel, and Al13Fe4 and Al5Fe2 act as crucial buffer layers. In this study, a consistent atomic-scale model for the Al13Fe4(010) parallel to Al5Fe2(001) interface is derived based on surface X-ray diffraction and theoretical calculations. Density functional theory calculations indicate that lattice mismatch and interfacial chemical composition are the main factors influencing the stability of the interface. Molecular dynamics simulations provide a mechanism for aluminum diffusion, explaining the formation of the complex Al13Fe4 and Al5Fe2 phases at the Al parallel to Fe interface.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Wilfried Bajoun Mbajoun, Yu-Chin Huang, Girma Hailu Gebresenbut, Cesar Pay Gomez, Vincent Fournee, Julian Ledieu
Summary: The oxidation process of the (100) surface of Au-Si-Ho quasicrystalline approximant was investigated using low-energy electron diffraction and X-ray photoelectron spectroscopy. The combination of these two techniques provided evidence for the segregation of Ho and Si on the surface induced by O2 adsorption, resulting in the loss of surface long-range order.
ISRAEL JOURNAL OF CHEMISTRY
(2023)
Article
Chemistry, Physical
Blaz Leskovar, Saso Sturin, Kemal Delijic, Julian Ledieu, Matejka Podlogar, Sandra Drev, Iztok Naglic, Bostjan Markoli
Summary: This study confirms that crystalline TiB2 particles can act as a potent site for the heterogeneous nucleation of the metastable icosahedral quasicrystalline phase (IQC) formed in cast Al-Mn-Si-Cu-Mg alloys. The results show that the primary IQC phase nucleates on facets of TiB2 particles and adopts different orientation relationships with the crystalline TiB2. Microstructural analyses reveal that inoculation has a noticeable influence on the size and distribution of the primary IQC phase, which subsequently affects the compressive properties of the alloys. These alloys have great potential for lightweight applications, especially in the automotive and aerospace industries.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Inorganic & Nuclear
Pascal Boulet, Marie-Cecile de Weerd, Emilie Gaudry, Saso Strum, Julien Zollinger, Jean-Marie Dubois, Vincent Fournee, Julian Ledieu
Summary: A binary phase with Al4Ir composition has been discovered and studied in terms of its structure and properties. This compound exhibits metastable behavior and its structure is derived from the ordering of aluminum atoms, which replace nickel atoms in the prototype structure. The deviation from the Hume-Rothery rule in terms of electron count and the presence of occupied antibonding states suggest the metastable nature of this compound.
INORGANIC CHEMISTRY
(2022)
Meeting Abstract
Chemistry, Multidisciplinary
J. Valentin, P. Boulet, G. Lengaigne, J. Ledieu, V. Fournee
ACTA CRYSTALLOGRAPHICA A-FOUNDATION AND ADVANCES
(2022)