Unveiling the nature of atomic defects in graphene on a metal surface

• Karl Rothe,
• Nicolas Néel and
• Jörg Kröger

Beilstein J. Nanotechnol. 2024, 15, 416–425, doi:10.3762/bjnano.15.37

• depressions with a measured repeat distance of 2.59 ± 0.05 nm reflects the moiré pattern that is caused by the lattice mismatch between graphene and Ir(111), where graphene directions are aligned with directions of the metal substrate [25][42][43][44][45]. The lozenge unit cell of the coincidence lattice is

• depicted in the bottom inset to Figure 1a, which shows an atomically resolved STM image of graphene. Mounds of the moiré pattern appear as depressions, while valleys show bright contrast at the specific tunneling parameters used for the STM topograph in Figure 1a. At higher tunneling currents, a contrast

• increased tip–graphene hybridization compared to the far tunneling range, which may entail a modification of the graphene electronic structure or enhance the contribution of substrate states to the junction current [46]. The mounds and adjacent valleys of the moiré superstructure are characterized by

Determining by Raman spectroscopy the average thickness and N-layer-specific surface coverages of MoS₂ thin films with domains much smaller than the laser spot size

• Felipe Wasem Klein,
• Jean-Roch Huntzinger,
• Vincent Astié,
• Damien Voiry,
• Romain Parret,
• Houssine Makhlouf,
• Sandrine Juillaguet,
• Jean-Manuel Decams,
• Sylvie Contreras,
• Périne Landois,
• Ahmed-Azmi Zahab,
• Jean-Louis Sauvajol and
• Matthieu Paillet

Beilstein J. Nanotechnol. 2024, 15, 279–296, doi:10.3762/bjnano.15.26

• super conductivity [21][22], non-linear optics [23][24], and moiré excitons [25]. Because the properties of MoS2 flakes are first a function of their thickness, or layer number (N), it is of a primary importance to determine the N of MoS2 flakes, including twisted MoS2 flakes and defective MoS2 flakes

• that in the latter flakes, new bands, named FLA and FTA, are superimposed to the second-order Raman spectra. The FLA and FTA modes in θ-2L-MoS2 are attributed, respectively, to folded longitudinal acoustic phonons and folded transverse acoustic phonons of the monolayer due to the presence of a moiré

• new mode, named FA′1, appears on the high-frequency side of the A1g mode. The FA′1 mode is identified as Raman scattering from moiré phonons associated with the A′1 dispersion curve of 1L-MoS2. It is folded onto the zone center and, consequently, becomes Raman active [20]. Obviously, its frequency

Investigation of electron-induced cross-linking of self-assembled monolayers by scanning tunneling microscopy

• Patrick Stohmann,
• Sascha Koch,
• Yang Yang,
• Christopher David Kaiser,
• Julian Ehrens,
• Jürgen Schnack,
• Niklas Biere,
• Dario Anselmetti,
• Armin Gölzhäuser and
• Xianghui Zhang

Beilstein J. Nanotechnol. 2022, 13, 462–471, doi:10.3762/bjnano.13.39

• (Figure 2a), similarly to what have been reported [64][65][66][67]. Figure 2b (top panel) shows a fast Fourier transform (FFT)-enhanced image of the α-phase, where the absence of Moiré-like superstructures indicates a commensurate molecular arrangement with respect to the Au surface. Figure 2e (top panel

Molecular assemblies on surfaces: towards physical and electronic decoupling of organic molecules

• Sabine Maier and
• Meike Stöhr

Beilstein J. Nanotechnol. 2021, 12, 950–956, doi:10.3762/bjnano.12.71

• applications [78], 2D materials, on the other hand, offer an alternative way for decoupling molecular structures from metal substrates [24]. 2D van der Waals materials are generally inert and therefore, are potentially well suited for physical decoupling of molecular structures. However, moiré patterns present

Local stiffness and work function variations of hexagonal boron nitride on Cu(111)

• Abhishek Grewal,
• Yuqi Wang,
• Matthias Münks,
• Klaus Kern and
• Markus Ternes

Beilstein J. Nanotechnol. 2021, 12, 559–565, doi:10.3762/bjnano.12.46

• the contact potential difference measured by Kelvin probe force microscopy. Using 3D force profiles of the same area we determine the relative stiffness of the Moiré region allowing us to analyse both electronic and mechanical properties of the 2D layer simultaneously. We obtain a sheet stiffness of

• -BN/Cu(111) substrate. Keywords: decoupling layers; hexagonal boron nitride; local stiffness; Moiré superstructure; work function variation; Introduction Two-dimensional hexagonal boron nitride (h-BN) is among the list of materials that garnered tremendous interest following the exfoliation of mono

• non-contact atomic force microscopy (nc-AFM) to study h-BN on Cu(111). This template has interesting properties because the dielectric layer is only very weakly bound to the metal and shows an electronically induced Moiré superstructure [25][26]. First STM studies on this system pointed to only a

Reconstruction of a 2D layer of KBr on Ir(111) and electromechanical alteration by graphene

• Zhao Liu,
• Antoine Hinaut,
• Stefan Peeters,
• Sebastian Scherb,
• Ernst Meyer,
• Maria Clelia Righi and
• Thilo Glatzel

Beilstein J. Nanotechnol. 2021, 12, 432–439, doi:10.3762/bjnano.12.35

• contrast, on hexagonal (111) oriented metal surfaces, alkali halides were reported to arrange in cubic islands [31][32][33]. Sometimes, they exhibit a moiré pattern, for example, as a result of the incommensurate growth in the system of NaCl/Cu(111) [34]. Furthermore, considering the interface of alkali

• a new surface structure, different from the one on other metal substrates such as Cu(111) [42]. Now, the question arises if this structure is a moiré lattice (lateral relaxation) induced by an alternating strength of interaction forces or a new reconstruction of the KBr layer. To search for this

• presented in Supporting Information File 1, Figure S2. Initially, a system with a periodicity of Ir(111) along the direction of 21 × aIr and along of × aIr (21 × ) was considered, resulting in a moiré pattern similar to the experimental observations. The structural optimization in a variable cell of this

TiO_x/Pt₃Ti(111) surface-directed formation of electronically responsive supramolecular assemblies of tungsten oxide clusters

• Marco Moors,
• Yun An,
• Agnieszka Kuc and
• Kirill Yu. Monakhov

Beilstein J. Nanotechnol. 2021, 12, 203–212, doi:10.3762/bjnano.12.16

• -wheel-like structural motif. The complex pattern of this hexagonally shaped titanium oxide film is due to the moiré effect on the underlying metallic substrate. Both phases consist of an oxygen-terminated bilayer with a stoichiometric TiO phase [22], such that the structural differences are triggered by

• purpose, an oxide surface with a lower defect concentration should be more promising. W3O9 adsorption on the w’-TiOx phase grown on Pt3Ti(111) Figure 2a and Figure 2b show the less defective w’-TiOx phase with its characteristic wagon-wheel structure caused by a moiré pattern of the Ti–O bilayer and the

• unit cell size of 3.18 Å, which is rotated by 3.5° on the alloy substrate with an interatomic Pt atom distance of 2.76 Å, the observed moiré pattern can be simulated [23][26]. In contrast to the z’-TiOx phase, the amount of surface holes is negligibly low, although the oxide film is still atomically

Adsorption and self-assembly of porphyrins on ultrathin CoO films on Ir(100)

• Feifei Xiang,
• Tobias Schmitt,
• Marco Raschmann and
• M. Alexander Schneider

Beilstein J. Nanotechnol. 2020, 11, 1516–1524, doi:10.3762/bjnano.11.134

• earlier studies [18][20]. A 1BL CoO(111) film exhibits a corrugated, slightly distorted cobalt oxide bilayer (Figure 2a,b). It forms a one-dimensional moiré on the Ir(100) surface with perfect row matching resulting in a superstructure between c(8 × 2) and c(10 × 2) with respect to the Ir(100) surface

Self-assembly and spectroscopic fingerprints of photoactive pyrenyl tectons on hBN/Cu(111)

• Domenik M. Zimmermann,
• Knud Seufert,
• Luka Ðorđević,
• Tobias Hoh,
• Sushobhan Joshi,
• Tomas Marangoni,
• Davide Bonifazi and
• Willi Auwärter

Beilstein J. Nanotechnol. 2020, 11, 1470–1483, doi:10.3762/bjnano.11.130

• as such spacer layers [18] and can promote site-dependent decoupling and adsorption [19][20], yielding access to optical transitions [21] as well as allowing for orbital-resolved STM imaging [19][21][22][23]. For instance, hBN/Cu(111) [24][25][26][27] features a work function template with a moiré

• underlying hBN/Cu(111) support. This template featured a moiré pattern with areas of low local work function (pores, P) and high local work function (wires, W) [25][29][30], which was reflected by the molecular level alignment, as measured by dI/dV spectroscopy [28][35][36][37]. On pore areas, the MOs were

• on (or near) wire areas. Accordingly, the periodic modulation of the pyrene electronic structure induced by the moiré pattern of the underlying hBN/Cu(111) could directly be visualized in STM images recorded at suitable sample bias voltages (see Figure 2a, Figure 4a and Figure 5a, 5c, 5d, as well as

Scanning tunneling microscopy and spectroscopy of rubrene on clean and graphene-covered metal surfaces

• Karl Rothe,
• Alexander Mehler,
• Nicolas Néel and
• Jörg Kröger

Beilstein J. Nanotechnol. 2020, 11, 1157–1167, doi:10.3762/bjnano.11.100

• ) reconstruction. As Figure 4d shows, nearly equivalent adsorption sites are occupied by the C42H28 molecules every 4a along the discommensuration lines. Therefore, the additional periodic pattern is due to a moiré effect along the soliton walls. A similar matching of the molecular superstructure with the Au(111

• molecular island adjacent to clean graphene, which exhibits a moiré pattern (inset to Figure 6a). The unit cell of the regular molecular superstructure can be inferred from the close-up view in Figure 6b. The lattice vectors are a and b with (crystallographic direction of the graphene lattice, marked by

• . A template effect of graphene or a moiré lattice on the molecular assembly was not identified. Merely the orientation of the tetracene backbone perpendicular to a graphene crystallographic direction was observed. A finite residual coupling of the molecule to graphene-covered Pt(111) is likewise

Monolayers of MoS₂ on Ag(111) as decoupling layers for organic molecules: resolution of electronic and vibronic states of TCNQ

• Asieh Yousofnejad,
• Gaël Reecht,
• Nils Krane,
• Christian Lotze and
• Katharina J. Franke

Beilstein J. Nanotechnol. 2020, 11, 1062–1071, doi:10.3762/bjnano.11.91

• of MoS2 on a metal surface [34]. The islands exhibit a characteristic hexagonal pattern reflecting a moiré structure, which results from the lattice mismatch between the Ag(111) surface and MoS2 (Figure 1b). Areas with large apparent height correspond to domains in which the S atoms sit on top of Ag

• atoms, whereas the lower areas represent two different hollow sites (fcc or hcp stacking) of the S atoms on the Ag lattice. The most abundant moiré periodicity amounts to approx. 3.3 ± 0.1 nm. This value is similar to the one observed for MoS2 on Au(111) [29][32][34][37]. Given the similar lattice

• constants of Au (4.08 Å) and Ag (4.09 Å), a locking into a similar superstructure at the metal–MoS2 interface is not surprising. However, occasionally, we also observe moiré patterns with lattice constants of 3.6 ± 0.1 and 3.0 ± 0.1 nm, and different angles between MoS2 and the Ag(111) lattice. This

Direct observation of oxygen-vacancy formation and structural changes in Bi₂WO₆ nanoflakes induced by electron irradiation

• Hong-long Shi,
• Bin Zou,
• Zi-an Li,
• Min-ting Luo and
• Wen-zhong Wang

Beilstein J. Nanotechnol. 2019, 10, 1434–1442, doi:10.3762/bjnano.10.141

• bonds of these thin nanoflakes [14]. Electron irradiation of an individual nanoflake through HRTEM In order to avoid secondary electron scattering and moiré fringes in HRTEM imaging, we selected a well-isolated individual nanoflake of ca. 70 nm in size for electron irradiation experiments. The size of

Capillary force-induced superlattice variation atop a nanometer-wide graphene flake and its moiré origin studied by STM

• Loji K. Thomas and
• Michael Reichling

Beilstein J. Nanotechnol. 2019, 10, 804–810, doi:10.3762/bjnano.10.80

• Loji K. Thomas Michael Reichling Fachbereich Physik, Universität Osnabrück, Barbarastr. 7, 49076 Osnabrück, Germany Department of Physics, S. B College, Mahatma Gandhi University, Kerala, 686101, India 10.3762/bjnano.10.80 Abstract We present strong experimental evidence for the moiré origin of

• sufficient to account for the total expenditure of energy involved in the process. Keywords: capillary force; graphene; graphite; HOPG; moiré; solid–liquid interface; STM; superlattice; Introduction Graphite is a layered material with graphene sheets arranged in ABAB stacking. HOPG is an ordered form of

• of altering the superlattice on the flake. The change in the superlattice periodicity is then used to validate the moiré origin of the superlattices. We also describe the theory behind the plausible cause of the rotation of the flake based on a more “realistic” meniscus pertinent to the situation of

Investigation of CVD graphene as-grown on Cu foil using simultaneous scanning tunneling/atomic force microscopy

• Majid Fazeli Jadidi,
• Umut Kamber,
• Oğuzhan Gürlü and
• H. Özgür Özer

Beilstein J. Nanotechnol. 2018, 9, 2953–2959, doi:10.3762/bjnano.9.274

• preparation [7][8][9][10]. Also, large hexagonal periodic arrays, known as moiré patterns, with periodicities of several nanometers were reported [10][11][12][13]. These periodic moiré patterns were generally attributed to rotational misorientation of layers, lattice mismatch or subsurface defects. Despite

High-throughput synthesis of modified Fresnel zone plate arrays via ion beam lithography

• Kahraman Keskinbora,
• Umut Tunca Sanli,
• Margarita Baluktsian,
• Corinne Grévent,
• Markus Weigand and
• Gisela Schütz

Beilstein J. Nanotechnol. 2018, 9, 2049–2056, doi:10.3762/bjnano.9.194

• are due to a moiré effect during imaging. c) Top-right part of the FZP. 60 nm wide periods can be seen. d) The line profile taken from a region roughly 30 pixels wide marked in c. The lines written with the ion beam are fitted with a Gaussian curve with an average FWHM of 15 ± 3 nm. The measured line

Metal-free catalysis based on nitrogen-doped carbon nanomaterials: a photoelectron spectroscopy point of view

• Mattia Scardamaglia and
• Carla Bittencourt

Beilstein J. Nanotechnol. 2018, 9, 2015–2031, doi:10.3762/bjnano.9.191

• influenced by the substrate that supports the graphene sample. Both the morphology (moiré pattern) and the electronic interaction play a role in the selectivity of preferential N sites [92][99]. The amount of nitrogen is also an important parameter to preserve the stability and the electronic properties of

Recent highlights in nanoscale and mesoscale friction

• Andrea Vanossi,
• Dirk Dietzel,
• Andre Schirmeisen,
• Ernst Meyer,
• Rémy Pawlak,
• Thilo Glatzel,
• Marcin Kisiel,
• Shigeki Kawai and
• Nicola Manini

Beilstein J. Nanotechnol. 2018, 9, 1995–2014, doi:10.3762/bjnano.9.190

• direct information on the crystal structure itself. Particularly when the FFM tip is subject to stick–slip advancement, this mode becomes especially efficient for resolving structural features. By mapping the power dissipated by these lateral forces, FFM can even detect such elusive structures as moiré

• lubricant advancing at a fixed fraction of the sliding speed. This quantized velocity was understood as due to the moiré pattern of solitons generated by the lattice mismatch between the lubricant and one of the sliders being dragged forward by the other slider [135][136]. This phenomenon, besides being

• annealing, dehalogenation as well as cyclodehydrogenation can be achieved, which leads to clean, defect-free GNRs. Therefore, ideal contacts, free of contaminants, can be grown on the gold surface. The GNRs are observed to move preferentially in the [−101] direction, where the moiré pattern forming with Au

Adsorption and electronic properties of pentacene on thin dielectric decoupling layers

• Sebastian Koslowski,
• Daniel Rosenblatt,
• Alexander Kabakchiev,
• Klaus Kuhnke,
• Klaus Kern and
• Uta Schlickum

Beilstein J. Nanotechnol. 2017, 8, 1388–1395, doi:10.3762/bjnano.8.140

• to the lattice mismatch to Rh(111), the h-BN forms a buckled moiré superstructure [12]. The subsequently deposited pentacene molecules are preferentially found at the edges of the valleys of the h-BN moiré superstructure (Figure 1), similarly to what was observed for the CuPc/h-BN/Rh(111) system [13

• 2.8 Å using calculations for the h-BN/Rh(111) system based on the local distance of the h-BN layer from the metal substrate at the position of the pentacene molecule [12]. Thereby no electric field caused by an in-plane dipole moment of the rim induced by the hBN moiré pattern was considered. A value

Comprehensive Raman study of epitaxial silicene-related phases on Ag(111)

• Dmytro Solonenko,
• Ovidiu D. Gordan,
• Guy Le Lay,
• Dietrich R. T. Zahn and
• Patrick Vogt

Beilstein J. Nanotechnol. 2017, 8, 1357–1365, doi:10.3762/bjnano.8.137

• prepare dominant multiple or single domains. At higher preparation temperatures the “” symmetry becomes dominant in LEED measurements and is finally observed solely for deposition temperatures above 250 °C (Figure 1d, inset). The STM topography image of this debated structure (Figure 1d) reveals a Moiré

• -like surface pattern [6][16]. This pattern originates from locally ordered areas that are surrounded by distorted or disordered zones. The ordered areas appear brighter in filled-states STM images, thus mimicking a Moiré pattern. Because of the inherent intrinsic disorder (ID) it is not reasonable to

Organoclay hybrid materials as precursors of porous ZnO/silica-clay heterostructures for photocatalytic applications

• Marwa Akkari,
• Pilar Aranda,
• Abdessalem Ben Haj Amara and
• Eduardo Ruiz-Hitzky

Beilstein J. Nanotechnol. 2016, 7, 1971–1982, doi:10.3762/bjnano.7.188

• the final heterostructures (Figure 4) one can observe: i) the presence of delaminated clay platelets (the region indicated by the arrow in Figure 4A and 4B); ii) the presence of ZnO NP (showing in some cases Moiré fringes, Figure 4C); and iii) the presence of aggregates of SiO2 NP which in some cases

• ) ZnO/SiO2-TSM, in both images the arrows show regions with the presence of delaminated clay particles (CLO and TSM, respectively). Image (C) represents a detail of A at higher magnification showing a ZnO nanoparticle within the silica matrix (M arrow: Moiré fringe). N2 adsorption–desorption isotherms

Distribution of Pd clusters on ultrathin, epitaxial TiO_x films on Pt₃Ti(111)

• Christian Breinlich,
• Maria Buchholz,
• Marco Moors,
• Tobias Pertram,
• Conrad Becker and
• Klaus Wandelt

Beilstein J. Nanotechnol. 2015, 6, 2007–2014, doi:10.3762/bjnano.6.204

• (i.e., oxygen vacancies) in this structure are confined to these trenches and act as nucleation sites. Therefore, the Pd clusters are mostly arranged in unidirectional rows along the trenches, creating a template effect. The second phase, w'-TiOx, exhibits a hexagonal, long range, (7 × 7)R21.8°, Moiré

• the Moiré superstructure of ultrathin aluminium oxide films grown on the chemically ordered, Ni3Al(111) surface [11][12][13][14]. The advantages of growing an oxide film from a component of an ordered alloy surface with a higher enthalpy of oxide formation are the somewhat better structural quality of

• the resulting films and their improved reproducibility compared to films grown by “reactive evaporation” [7]. Both the z'-TiOx phase on Pt(111) and the Moiré superstructure of the alumina film on Ni3Al(111) have already been proven to be excellent templates for the ordered growth of metal clusters

Structure and mechanism of the formation of core–shell nanoparticles obtained through a one-step gas-phase synthesis by electron beam evaporation

• Andrey V. Nomoev,
• Sergey P. Bardakhanov,
• Makoto Schreiber,
• Dashima G. Bazarova,
• Nikolai A. Romanov,
• Boris B. Baldanov,
• Bair R. Radnaev and
• Viacheslav V. Syzrantsev

Beilstein J. Nanotechnol. 2015, 6, 874–880, doi:10.3762/bjnano.6.89

• to the core–shell particles, a few particles were observed with very uneven or possibly incomplete shells (Figure 3). These particles had spots with what appeared to be moiré patterns; interference patterns which form due to differences in the lattice orientation between two crystal planes. Moiré

• patterns can occur due to two identical planes being rotated with respect to one another, two parallel planes with dissimilar spacings, or a combination of the two. SAED measurements on these regions showed the presence of Cu(111), Cu2O(111), and a moiré spacing of 1.3100 nm. The moiré spacing, D, between

• two phases can be calculated by where d1 and d2 are the interplanar spacings of the two phases and α is the angle between the two lattices [12]. Fitting the measured moiré spacing to the moiré spacing calculated based on the measured d-spacings, a relative angle of α = 0.093° was fitted. Thus, the

Nanoporous Ge thin film production combining Ge sputtering and dopant implantation

• Jacques Perrin Toinin,
• Alain Portavoce,
• Khalid Hoummada,
• Michaël Texier,
• Maxime Bertoglio,
• Sandrine Bernardini,
• Marco Abbarchi and
• Lee Chow

Beilstein J. Nanotechnol. 2015, 6, 336–342, doi:10.3762/bjnano.6.32

• annealing, leaving deep holes in the Ge film. The image contrast is affected by the variation of both local diffraction conditions and absorption. The moiré pattern visible in various areas of the deposited layer confirms its polycrystalline structure. The pores are difficult to observe in the cross

Synthesis, characterization, monolayer assembly and 2D lanthanide coordination of a linear terphenyl-di(propiolonitrile) linker on Ag(111)

• Zhi Chen,
• Svetlana Klyatskaya,
• José I. Urgel,
• David Écija,
• Olaf Fuhr,
• Willi Auwärter,
• Johannes V. Barth and
• Mario Ruben

Beilstein J. Nanotechnol. 2015, 6, 327–335, doi:10.3762/bjnano.6.31

• Moiré pattern. After the exposure of the molecular monolayer to a beam of Gd atoms, the propiolonitrile groups get readily involved in metal–ligand coordination interactions. Distinct coordination motifs evolve with coordination numbers varying between three and six for the laterally-bound Gd centers

• investigation of the self-assembly of the organic linker 2 on a Ag(111) surface revealed a densely packed, chevron monolayer exhibiting a Moiré pattern. In contrast, lanthanide coordination of the same ligand 2 with Gd atoms resulted in metal–organic networks with only local order. These latter results differ

• molecules of NC–C≡C–Ph3–C≡C–CN (2) were clearly resolved as rod-like protrusions showing a chevron arrangement but now exhibiting an additional Moiré pattern (Figure 3). The latter results from the superposition of the monolayer and substrate symmetries, rotated by an angle showing the very subtle balance

Overview about the localization of nanoparticles in tissue and cellular context by different imaging techniques

• Anja Ostrowski,
• Daniel Nordmeyer,
• Alexander Boreham,
• Cornelia Holzhausen,
• Lars Mundhenk,
• Christina Graf,
• Martina C. Meinke,
• Annika Vogt,
• Sabrina Hadam,
• Jürgen Lademann,
• Eckart Rühl,
• Ulrike Alexiev and
• Achim D. Gruber

Beilstein J. Nanotechnol. 2015, 6, 263–280, doi:10.3762/bjnano.6.25

• multiplication of the obtained pattern, so-called moiré fringes can be seen as stripes in the overlapping regions. These moiré fringes contain information about the unknown structure and the observer gains access to normally unresolvable information in the sample [115]. Thus, multiple images with different