Restructuring of an Ir(210) electrode surface by potential cycling

• Khaled A. Soliman,
• Dieter M. Kolb,
• Ludwig A. Kibler and
• Timo Jacob

Beilstein J. Nanotechnol. 2014, 5, 1349–1356, doi:10.3762/bjnano.5.148

• cooling in nitrogen gas atmosphere [19][20]. Such thermally-induced faceted Ir(210) has been characterized by cyclic voltammetry and in situ scanning tunnelling microscopy (STM) [20]. Thus, very similar surface structures with nanometer-scale pyramids consisting of (110) and {311} facets could be prepared

• that the faceting process of Ir(210) can also be induced by the electrode potential [19]. Here, we present a combined electrochemical and in situ STM study of Ir(210), which demonstrates that the faceted surface is not only stable in a certain potential region, but can also be obtained

• to study the electrocatalytic activity of restructured Ir(210) surfaces compared to non-restructured Ir(210). Experimental A cylindrical Ir(210) single crystal (4 mm in diameter and thickness, MaTecK Jülich, Germany) was used both for electrochemical and in situ STM investigations. Before each

Sublattice asymmetry of impurity doping in graphene: A review

• James A. Lawlor and
• Mauro S. Ferreira

Beilstein J. Nanotechnol. 2014, 5, 1210–1217, doi:10.3762/bjnano.5.133

• -Khosousi et al. [41] who again used the CVD growth process but with a pyridine (C5H5N) precursor for the nitrogen and graphene instead of the conventional ammonia/methane mix. Figure 2 shows a rather striking STM image of a large area of N-doped graphene grown using this method, showing two clearly defined

• lattice with the most common experimentally observed species of substitutional nitrogen dopants: (A) a single graphitic, (B) three pyridinics, (C) one N2AA pair, (D) one N2AB pair and (E) one N2AB′ pair. STM images of nitrogen doped graphene on (a) 7 nm2, (b) 20 nm2 and (c) 100 nm2 scales, adapted with

• permission from Zabet-Khosousi et al. [41]. Copyright 2014 American Chemical Society. The dopants locations are identified by finding bright spots on the STM image, corresponding to slight perturbations in the positions of the neighbouring carbon atoms. The dopant sublattice can be found through the

Classical molecular dynamics investigations of biphenyl-based carbon nanomembranes

• Andreas Mrugalla and
• Jürgen Schnack

Beilstein J. Nanotechnol. 2014, 5, 865–871, doi:10.3762/bjnano.5.98

• [4][17]. Are STM investigations able to discriminate between the scenarios [3][21][23]? Are gas permeation experiments and bulge tests of Young’s moduli meaningful checks of the structure [16]? And how do our findings transfer to the many other nanomembranes produced from very different precursors

DNA origami deposition on native and passivated molybdenum disulfide substrates

• Xiaoning Zhang,
• Masudur Rahman,
• David Neff and
• Michael L. Norton

Beilstein J. Nanotechnol. 2014, 5, 501–506, doi:10.3762/bjnano.5.58

• to adsorb through van der Waals forces between the four nitrogenous nucleobases and the basal plane of MoS2 [18]. For example, in the report of Maddocks et al. [21], guanine, one of the four DNA bases, was observed, by using scanning tunneling microscopy (STM), to form a stable two-dimensional

Fullerenes as adhesive layers for mechanical peeling of metallic, molecular and polymer thin films

• Maria B. Wieland,
• Anna G. Slater,
• Barry Mangham,
• Neil R. Champness and
• Peter H. Beton

Beilstein J. Nanotechnol. 2014, 5, 394–401, doi:10.3762/bjnano.5.46

• cycles of sputtering and annealing until a clear herringbone reconstruction pattern could be observed on the Au(111) surface using scanning tunnelling microscopy (STM). See the Experimental section for more details. Fullerene films with thickness ranging from 5 nm to 100 nm were deposited via sublimation

• transfer of porphyrin polymers onto a target dielectric substrate. An extended covalently linked network of TBPP was prepared by sublimation onto a heated substrate as described in the Experimental section. An STM image of the resulting surface (Figure 4) shows small regions of local square order with

• sublimation of organic thin films and house the STM has a base pressure of 10−10 mbar. Commercially supplied (111) terminated gold films on mica (Georg Albert, Physical Vapor Deposition) are used as substrates and prepared via Ar-sputtering for 30 min at 0.8 keV and 10−5 mbar Ar-pressure, followed by

Uncertainties in forces extracted from non-contact atomic force microscopy measurements by fitting of long-range background forces

• Adam Sweetman and
• Andrew Stannard

Beilstein J. Nanotechnol. 2014, 5, 386–393, doi:10.3762/bjnano.5.45

• extrapolation method. Keywords: background subtraction; DFM; F(z); force; atomic resolution; NC-AFM; Si(111); STM; van der Waals; Introduction Non-contact atomic force microscopy (NC-AFM) is now the tool of choice for surface scientists wishing to investigate interatomic and intermolecular forces on surfaces

• uncertainties may result from short-range forces extracted by this method on surfaces where no check is available. Methods The data in this paper were acquired using an Omicron Nanotechnology GmbH combined LT-STM/NC-AFM operating in UHV and at cryogenic temperatures (78 K at LN2). Clean Si(111)-(7 × 7) samples

• , and, based on previous measurements of similar sensors [5][15], assume an effective stiffness of k ≈ 2000 N/m. The sensors were first prepared on a clean silicon surface by standard STM techniques (pulsing and indentation) until good STM and NC-AFM resolution was achieved. Typically we used

Exploring the complex mechanical properties of xanthan scaffolds by AFM-based force spectroscopy

• Hao Liang,
• Guanghong Zeng,
• Yinli Li,
• Shuai Zhang,
• Huiling Zhao,
• Lijun Guo,
• Bo Liu and
• Mingdong Dong

Beilstein J. Nanotechnol. 2014, 5, 365–373, doi:10.3762/bjnano.5.42

• experiments were performed after 15 min of stabilization. Atomic force microscopy AFM imaging: AFM measurements were conducted on a commercial Agilent AFM/STM 5500 microscope (Agilent Technologies, USA) in contact mode. Nitride silicon cantilevers (OMCL-TR400PSA-1) with a spring constant of 0.02 N/m and a

Control theory for scanning probe microscopy revisited

• Julian Stirling

Beilstein J. Nanotechnol. 2014, 5, 337–345, doi:10.3762/bjnano.5.38

• the scanning tunnelling microscope (STM). The results are, however, equally applicable to other forms of SPM. For analysis of the full feedback loop of an STM (Figure 3) we start by considering that at any time t the tip will be above a particular area of the sample with height Z. Thus, the tip

• The measured tunnelling current is a function of the distance D(t), and also of the properties of the current-to-voltage (I–V) amplifier of the STM. As the tunnel current depends exponentially on the tip–sample distance the logarithm of the tunnel current is used for the feedback to improve the

• this becomes Feedback performance without mechanical modelling Initially we will study the stability of the STM feedback without modelling the mechanical resonances of the SPM system. For this we can substitute = 1 and Equation 15 into Equation 13. The feedback behaviour has been studied for four

Noncontact atomic force microscopy II

• Mehmet Z. Baykara and
• Udo D. Schwarz

Beilstein J. Nanotechnol. 2014, 5, 289–290, doi:10.3762/bjnano.5.31

• (STM). While it is possible to obtain atomic-resolution images of material surfaces by using STM with relative ease, its basic operational principle depends on the phenomenon of quantum tunneling, rendering the technique applicable only to conductive and semi-conductive samples. The atomic force

• microscope (AFM), which was invented only a few years after the introduction of the STM, overcame this fundamental limitation and was used with great success to image a number of sample surfaces with nanometer resolution without limitations associated with electrical conductivity. However, unlike the STM

Nanoscale patterning of a self-assembled monolayer by modification of the molecule–substrate bond

• Cai Shen and
• Manfred Buck

Beilstein J. Nanotechnol. 2014, 5, 258–267, doi:10.3762/bjnano.5.28

• the first thiol in the cathodic sweep of a voltammetric cycle and adsorb the other thiol during the anodic sweep. Results and Discussion Patterned UPD STM images of the UPD of copper on a BP2-modified Au substrate are shown in Figure 2. The typical topography of the SAM-covered substrate is seen in

• , the phase transition involved in the annealing is another process likely to contribute as discussed further below. Defects in the SAM are introduced by pulsing the STM tip. The extent of damage depends on the voltage, and a value of 4.5 V was used in this example, which generates defects about 6 nm in

• ambient environment the sample is exposed to the CuSO4 electrolyte and the UPD process is monitored in situ by electrochemical STM (EC-STM). According to the mechanism that is illustrated in Figure 1a [24] UPD starts at the defects and spreads radially. The EC-STM image of Figure 2c shows the surface

The role of surface corrugation and tip oscillation in single-molecule manipulation with a non-contact atomic force microscope

• Christian Wagner,
• Norman Fournier,
• F. Stefan Tautz and
• Ruslan Temirov

Beilstein J. Nanotechnol. 2014, 5, 202–209, doi:10.3762/bjnano.5.22

• , and qPlus-based non-contact atomic force (NC-AFM) microscopes can be a potent tool when applied to studies of single-molecule manipulation [6][11][15]. The STM function facilitates the effective preparation of the experiment while the NC-AFM, operated simultaneously with the STM, is used to control

• the structure and to measure the forces that act in the junction during the manipulation. Although, in principle, the conductance measured with the STM could also be used to control the structure during the manipulation of a molecule, the relation between the conductance and the structure of single

• -molecule junctions is still not generally understood and therefore the forces that act in the junction during the manipulation provide more direct information about the conformation of the molecule. One of the first attempts to manipulate large organic adsorbates with the tip of the LT-STM/NC-AFM has been

Core level binding energies of functionalized and defective graphene

• Toma Susi,
• Markus Kaukonen,
• Paula Havu,
• Mathias P. Ljungberg,
• Paola Ayala and
• Esko I. Kauppinen

Beilstein J. Nanotechnol. 2014, 5, 121–132, doi:10.3762/bjnano.5.12

• single carbon atom still cannot satisfy its chemically reactive dangling bond, as has been directly observed by scanning tunneling microscopy (STM) in high vacuum [11]. To address these important systems, and the potential shortcomings of previous studies, we have calculated graphene core level binding

Influence of the adsorption geometry of PTCDA on Ag(111) on the tip–molecule forces in non-contact atomic force microscopy

• Gernot Langewisch,
• Jens Falter,
• André Schirmeisen and
• Harald Fuchs

Beilstein J. Nanotechnol. 2014, 5, 98–104, doi:10.3762/bjnano.5.9

• dianhydride (PTCDA) adsorbed on the Ag(111) surface is a prototypical organic–anorganic interface that has been investigated by a large variety of different methods in the past [1]. Based on scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS) experiments as well as theoretical

• measurements on the same system have been published before [3][13]. Figure 1a shows an STM topography image of a PTCDA monolayer on Ag(111). The molecules are arranged in a characteristic herring bone structure where the unit cell contains two molecules with different orientation and adsorption geometry. Here

• stronger repulsion and, thus, less attractive net forces near the minimum of the FTS(z) curves. Please note that no STM measurements were performed on the surface area investigated by the 3D force spectroscopy. Therefore, it is not possible to unambiguously verify this proposed relationship between

Some reflections on the understanding of the oxygen reduction reaction at Pt(111)

• Ana M. Gómez-Marín,
• Ruben Rizo and
• Juan M. Feliu

Beilstein J. Nanotechnol. 2013, 4, 956–967, doi:10.3762/bjnano.4.108

• ” defects in such a way that the terraces remain ordered. This was observed by STM, which shows that the defects seem to concentrate at the step lines and leave reasonably wide terraces between them [16][63][64]. Following this strategy, several experiments have shown that in acidic solutions Pt(111) is

STM tip-assisted engineering of molecular nanostructures: PTCDA islands on Ge(001):H surfaces

• Amir A. Ahmad Zebari,
• Marek Kolmer and
• Jakub S. Prauzner-Bechcicki

Beilstein J. Nanotechnol. 2013, 4, 927–932, doi:10.3762/bjnano.4.104

• shown in case of Si(001) [17], Si(111) [18] and Ge(001) [19] surfaces that such a passivating layer electronically decouples the molecule from the substrate and increases their mobility. In this article, high-resolution scanning tunneling microscope (STM) measurements of self-assembled perylene-3,4,9,10

• -tetracarboxylic dianhydride (PTCDA) molecular islands on a hydrogen passivated germanium surface, Ge(001):H, are presented. The application of bias voltage pulses in STM allows for the modification of the islands. We found that the presence of a scanning tip of the tunneling microscope facilitates and speeds the

• on top of the islands in rt STM (see Figure 1a). These images show that the islands have crystalline character, and the top-most layer closely resembles the herringbone structure found for the (102) plane of PTCDA bulk crystal [21][22]. Similar arrangements have been reported for the Si(001):H/PTCDA

Adsorption of the ionic liquid [BMP][TFSA] on Au(111) and Ag(111): substrate effects on the structure formation investigated by STM

• Benedikt Uhl,
• Florian Buchner,
• Dorothea Alwast,
• Nadja Wagner and
• R. Jürgen Behm

Beilstein J. Nanotechnol. 2013, 4, 903–918, doi:10.3762/bjnano.4.102

• reconstruction plays a major role in the structure formation of the 2D crystalline phase. In combination with recent density functional theory calculations, the sub-molecularly resolved STM images allow to clearly discriminate between the [BMP]+ cation and [TFSA]− anion. Keywords: adsorption; Ag; Au; [BMP][TFSA

• spectroscopic techniques such as ultraviolet photoelectron spectroscopy (UPS) [15][16], X-ray photoelectron spectroscopy (XPS) [17][18][19][20][21], or temperature programmed desorption (TPD) [22], as well as scanning probe microscopies (scanning tunnelling microscopy (STM) and atomic force microscopy (AFM

• temperature adsorption Previous STM studies by Waldmann et al. and by Foulston et al. on the structure and structure formation of IL thin films on single crystal substrates, specifically for 1-butyl-1-methylpyrrolidinium-tris(pentafluoroethyl)trifluorophosphate [BMP][FAP] adsorption on Au(111) [24] and for 1

Digging gold: keV He⁺ ion interaction with Au

• Vasilisa Veligura,
• Gregor Hlawacek,
• Robin P. Berkelaar,
• Raoul van Gastel,
• Harold J. W. Zandvliet and
• Bene Poelsema

Beilstein J. Nanotechnol. 2013, 4, 453–460, doi:10.3762/bjnano.4.53

• an atomically flat gold surface was observed by scanning tunneling microscopy (STM) [13][14]. Mounds with spacing of a few nanometers were formed. In the current work we have studied the He+-ion-induced modifications of crystalline gold samples due to sputtering, helium implantation and defect

Ni nanocrystals on HOPG(0001): A scanning tunnelling microscope study

• Michael Marz,
• Keisuke Sagisaka and
• Daisuke Fujita

Beilstein J. Nanotechnol. 2013, 4, 406–417, doi:10.3762/bjnano.4.48

• [7][8]. Various methods are employed for growing metallic clusters on surfaces such as ion sputtering [9], pulsed laser deposition [10], electro deposition [11][12][13], vapor deposition [14], aerosol deposition [15], material transfer of an STM tip [16], etc. For the formation of nanoparticles a

• experimental conditions has been performed by means of scanning tunnelling microscopy (STM) measurements. We show that Ni clusters are formed following a monomodal distribution, and that mild annealing can transform the Ni particles into single crystals. Within the annealing process two distinguishable regimes

• are observed. Additionally, we demonstrate the possibility to pick up single clusters from the surface in a controlled way, and we propose a model to understand the basics of the pick-up process. Experimental All measurements were performed in an UHV-STM system from Unisoku (USM-1200) at liquid

Optimal geometry for a quartz multipurpose SPM sensor

• Julian Stirling

Beilstein J. Nanotechnol. 2013, 4, 370–376, doi:10.3762/bjnano.4.43

• Julian Stirling School of Physics and Astronomy, The University of Nottingham, University Park, Nottingham, NG7 2RD, United Kingdom 10.3762/bjnano.4.43 Abstract We propose a geometry for a piezoelectric SPM sensor that can be used for combined AFM/LFM/STM. The sensor utilises symmetry to provide

• ; mechanical vibrations; scanning probe microscopy; scanning tunnelling microscopy; Introduction The heart of any scanning probe microscope (SPM) is its sensory probe. For a scanning tunnelling microscope (STM) this is simply an electrically conducting wire with an atomically sharp apex. For atomic force

• ] respectively, into a wide range of specialised sensors. The most common NC-AFM sensors: silicon microcantilvers [5], and quartz sensors such as the qPlus sensor (tuning fork) [6] or KolibriSensor® [7], have all been used for combined AFM/STM [7][8][9]. Combined AFM/LFM sensors have been constructed from

Influence of the solvent on the stability of bis(terpyridine) structures on graphite

• Daniela Künzel and
• Axel Groß

Beilstein J. Nanotechnol. 2013, 4, 269–277, doi:10.3762/bjnano.4.29

• help to explain experimental observations in the adsorption behavior of BTPs on graphite [11][12]. One example is the observation of blurred STM images of phthalocyanine molecules adsorbed as guest molecules in a BTP host network, which is due to the fact that rotations of the host molecules are hardly

• hindered by barriers [6][11]. Recently it was shown by scanning tunneling microscopy (STM) experiments that 3,3′-BTP exhibits a variety of adlayer structures at the interface between highly oriented pyrolytic graphite (HOPG) and the liquid as a function of the concentration in solution [6]. The resulting

Determining cantilever stiffness from thermal noise

• Jannis Lübbe,
• Matthias Temmen,
• Philipp Rahe,
• Angelika Kühnle and
• Michael Reichling

Beilstein J. Nanotechnol. 2013, 4, 227–233, doi:10.3762/bjnano.4.23

• described in our previous work as system B (UHV VT AFM/STM, Omicron NanoTechnology GmbH, Taunusstein, Germany) and as system C (UHV 750 variable temperature STM/AFM, RHK Technology, Inc., Troy, MI, USA) [6]. Temperatures used for data analysis are measured directly at the NC-AFM stage of a thermally

Thermal noise limit for ultra-high vacuum noncontact atomic force microscopy

• Jannis Lübbe,
• Matthias Temmen,
• Sebastian Rode,
• Philipp Rahe,
• Angelika Kühnle and
• Michael Reichling

Beilstein J. Nanotechnol. 2013, 4, 32–44, doi:10.3762/bjnano.4.4

• , the used laser light wavelength and the DC transimpedance of the preamplifier. The calibration of the detection system is described in Section 1 of Supporting Information File 1. System A is a room-temperature UHV AFM/STM (Omicron NanoTechnology GmbH, Taunusstein, Germany) equipped with an easyPLL

• (Nanosurf AG, Liestal, Switzerland) for frequency demodulation. The AFM/STM setup has been modified by replacing the light source (light-emitting diode exchanged with a laser diode) and using optimised preamplifiers. Preamplifiers have been optimised for low-noise operation at frequencies around 100 kHz and

• 685 nm, while the PSD has a spectral sensitivity of 0.45 A/W at this wavelength. Noise spectra are recorded with an SR770 spectrum analyser (Stanford Research Systems, Inc., Sunnyvale, CA, USA). System B is a UHV VT AFM/STM (Omicron NanoTechnology GmbH, Taunusstein, Germany) equipped with an easyPLL

Characterization of the mechanical properties of qPlus sensors

• Jan Berger,
• Martin Švec,
• Martin Müller,
• Martin Ledinský,
• Antonín Fejfar,
• Pavel Jelínek and
• Zsolt Majzik

Beilstein J. Nanotechnol. 2013, 4, 1–9, doi:10.3762/bjnano.4.1

• . Keywords: AFM; Cleveland’s method; cross talk; force; qPlus; stiffness; STM; thermal noise; tuning fork; Introduction The invention of scanning tunneling microscopy [1] and atomic force microscopy (AFM) [2] opened new horizons in characterization and modification of surfaces and nanostructures. STM is

• , including insulators. Shortly after the invention of AFM and STM, the first attempt to combine static AFM and STM measurements was made by Dürig et al. in 1986 [12]. A few years later, combined nc-AFM/STM using a Si cantilever was reported for the first time (see [13]), showing the capability to record

• simultaneous STM and AFM signals with atomic resolution on a metal surface [14]. At the same time F. J. Giessibl introduced so-called qPlus sensors [15], which allow simultaneous acquisition of the tunneling current and the forces with a small oscillation amplitude. This method increases substantially the

Advanced atomic force microscopy techniques

• Thilo Glatzel,
• Hendrik Hölscher,
• Thomas Schimmel,
• Mehmet Z. Baykara,
• Udo D. Schwarz and
• Ricardo Garcia

Beilstein J. Nanotechnol. 2012, 3, 893–894, doi:10.3762/bjnano.3.99

• introduced in the 19th century, the invention of the atomic force microscope (AFM) in 1986 by Binnig, Quate, and Gerber was a milestone for nanotechnology. The scanning tunneling microscope (STM), introduced some years earlier, had already achieved atomic resolution, but is limited to conductive surfaces

Pure hydrogen low-temperature plasma exposure of HOPG and graphene: Graphane formation?

• Baran Eren,
• Dorothée Hug,
• Laurent Marot,
• Rémy Pawlak,
• Marcin Kisiel,
• Roland Steiner,
• Dominik M. Zumbühl and
• Ernst Meyer

Beilstein J. Nanotechnol. 2012, 3, 852–859, doi:10.3762/bjnano.3.96

• . Scanning tunneling microscopy In order to corroborate the discussions of spectroscopy results further, scanning tunneling microscopy (STM) was utilized. STM image of pristine HOPG consists of a hexagonal pattern generated by the charge density of the electrons [37]. After exposure to hydrogen plasma, the

• calculation of a suspended graphane layer, where it is estimated that this layer should be corrugated in the form of ripples with an amplitude of a few hundred picometers [27]. The hexagonal ring patterns in Figure 5 appear in different distorted forms. Our STM images are similar to those obtained locally

• around the step edges of graphite, where the step edges were terminated with atomic hydrogen [38]. Since STM probes the local density of states [37], this distortion in the ring patterns may arise from surface corrugation [38]. On the other hand, it should not be disregarded that graphane has different