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

• tunnel current is measured, marking the jump of the molecule to the tip apex. A pentacene-functionalized STM tip might express a considerably smaller effective tip apex due to scanning with one of the π-orbitals of the attached pentacene molecule and thereby improves spatial resolution. Using a

Measuring adhesion on rough surfaces using atomic force microscopy with a liquid probe

• Juan V. Escobar,
• Cristina Garza and
• Rolando Castillo

Beilstein J. Nanotechnol. 2017, 8, 813–825, doi:10.3762/bjnano.8.84

• cantilever is obtained by multiplying its deflection by the spring constant of the cantilever. In the standard AFM technique, the tip apex typically has a radius of 5–50 nm, whereas the radii of colloidal probes are in the range of 1–100 μm, resulting in much higher adhesion forces. Mercury: Double distilled

Optimizing qPlus sensor assemblies for simultaneous scanning tunneling and noncontact atomic force microscopy operation based on finite element method analysis

• Omur E. Dagdeviren and
• Udo D. Schwarz

Beilstein J. Nanotechnol. 2017, 8, 657–666, doi:10.3762/bjnano.8.70

• densities are increased at material boundaries and locations where particularly high stress is expected [29][30][31]. Figure 1c exposes areas of high stress when a constant force F is applied at the tip apex, with bright colors reflecting higher stress. From a measurement of the resulting z displacement for

• 2) since the force pulls on the tip apex rather than then prong, some deformation will occur in the tip and, in particular, inside the glue. To determine quality factor Q, eigenfrequency f0, and perturbation Δy/Δz of the first eigenmode oscillation from motion in the main x–z oscillation plane, an

Customized MFM probes with high lateral resolution

• Óscar Iglesias-Freire,
• Miriam Jaafar,
• Eider Berganza and
• Agustina Asenjo

Beilstein J. Nanotechnol. 2016, 7, 1068–1074, doi:10.3762/bjnano.7.100

• ] to improve the detection of small domains. One can also find the use of nanomagnets with high anisotropy as MFM probes [13] and different approaches to control the final domain at the tip apex [14][15], seeking best sensitivity or resolution. However, the easiest interpretation of the results is

• magnetic material to be deposited at the tip apex. Unfortunately, this results in larger tip radii and subsequent lower lateral resolution; furthermore, the influence over the sample magnetic state can increase. Depending on the specific properties of each sample, a balance between resolution and

• magnetostatic tip–sample interaction as a function of the magnetic field. By assuming that the sample magnetization remains unchanged during the experiment (Hc >> Happlied), as is commonly assumed to be the case for magnetic hard disks, one can gain insight into the evolution of the spins at the tip apex with

Modelling of ‘sub-atomic’ contrast resulting from back-bonding on Si(111)-7×7

• Adam Sweetman,
• Samuel P. Jarvis and
• Mohammad A. Rashid

Beilstein J. Nanotechnol. 2016, 7, 937–945, doi:10.3762/bjnano.7.85

• common vacuum contaminant, our tip termination could also easily be a number of other common contaminants (for example H, OH or O), which would also suppress the chemical reactivity of the tip apex. Therefore our modelling, using CO parameters, is only intended to represent a ‘generic’ passivated tip. In

• ). Results Origin of triangular contrast in simulated images Figure 1 shows a comparison between experimental constant height Δf images (acquired during the same experimental run as [11]), and simulated constant height Δf images using a flexible, and very rigid, tip apex. In both cases the images have been

• in the chemical reactivity of the tip. This evolution in contrast is not reproduced in the simulations using a very stiff tip (right column), where the atoms of the Si(111)-7×7 surface remain spherical throughout. This highlights the essential requirement for considering the flexibility of the tip

Large area scanning probe microscope in ultra-high vacuum demonstrated for electrostatic force measurements on high-voltage devices

• Urs Gysin,
• Thilo Glatzel,
• Thomas Schmölzer,
• Adolf Schöner,
• Sergey Reshanov,
• Holger Bartolf and
• Ernst Meyer

Beilstein J. Nanotechnol. 2015, 6, 2485–2497, doi:10.3762/bjnano.6.258

• implemented. Additionally, the samples can be optically exited by an external light source (UV–vis) which is introduced by a separate light fibre. An in situ piezo-electric alignment stage allows to focus and position the light exactly below the cantilever tip apex. Therefore, the setup allows for the

Kelvin probe force microscopy for local characterisation of active nanoelectronic devices

• Tino Wagner,
• Hannes Beyer,
• Patrick Reissner,
• Philipp Mensch,
• Heike Riel,
• Bernd Gotsmann and
• Andreas Stemmer

Beilstein J. Nanotechnol. 2015, 6, 2193–2206, doi:10.3762/bjnano.6.225

• the following. Figure 1 shows a model calculation using typical cantilever and interaction parameters, summarising how much tip apex, cone, and beam of an AFM cantilever probe contribute to the measured KFM signal in AM and FM operation. Shown are the percentages of the contributions and corresponding

• different oscillation amplitudes (see Supporting Information File 1 for details). While tip apex and cone clearly dominate the FM-KFM signal, opening the avenue to high resolution quantitative imaging, the cantilever beam at a distance of 14 μm dominates the AM-KFM signal even close to the sample, which is

Virtual reality visual feedback for hand-controlled scanning probe microscopy manipulation of single molecules

• Philipp Leinen,
• Matthew F. B. Green,
• Taner Esat,
• Christian Wagner,
• F. Stefan Tautz and
• Ruslan Temirov

Beilstein J. Nanotechnol. 2015, 6, 2148–2153, doi:10.3762/bjnano.6.220

• PTCDA molecule. The tip was then approached to the surface until the operator observed a sudden jump in the I and Δf signals. Here the oxygen atom under the tip flipped up toward the tip apex, thereby establishing a chemical bond between the tip and the molecule [5][6]. Through this bond the molecule

• single failure of the tip–molecule bond. It is important to note that in the course of the manipulation experiments in Figure 4 the molecule was never fully detached from the surface in order to prevent a tip structure change from happening, e.g., due to a jump of the extracted molecule onto the tip apex

Controlled switching of single-molecule junctions by mechanical motion of a phenyl ring

• Yuya Kitaguchi,
• Satoru Habuka,
• Hiroshi Okuyama,
• Shinichiro Hatta,
• Tetsuya Aruga,
• Thomas Frederiksen,
• Magnus Paulsson and
• Hiromu Ueba

Beilstein J. Nanotechnol. 2015, 6, 2088–2095, doi:10.3762/bjnano.6.213

• , VS = ±0.5 V, and zero voltage [19][22]. We define the lateral position of the tip, x, as the nominal distance (i.e., before relaxations) along [001] between the Cu tip apex atom and the Cu bridge site containing the chalcogen bond. Also, we define the tip height, h, as the distance between the planes

• imaging the area. Also we can repeat the lift and release without changing the condition of the tip apex. Thus, the molecular junction can be reversibly switched by mechanical motion of a phenyl ring. As shown in [12] this switching mechanism is also supported by the calculated potential energy landscape

• nonequilibrium density matrix and Hamiltonian in the equations for the equilibrium forces [19][22]. One observes repulsive (attractive) forces between the tip apex and nearest C-atom at positive (negative) sample voltages, consistent with the electrostatic force to be expected in the applied electric field with

Lower nanometer-scale size limit for the deformation of a metallic glass by shear transformations revealed by quantitative AFM indentation

• Arnaud Caron and
• Roland Bennewitz

Beilstein J. Nanotechnol. 2015, 6, 1721–1732, doi:10.3762/bjnano.6.176

• from 19.5 to 170 pm/s. After drift correction the indentation curves coincide as expected in the low load regime that corresponds to the elastic deformation. A drawback of AFM indentation experiments is that no controlled manufacturing of the tip apex is available at the nanometer scale and one has to

• identify which granule or crystallite at the tip apex was the actual indenter. However, the shape of the AFM tip relevant for indentation and imaging can be reconstructed using the tip analysis function of Gwyddion [20]. Figure 3b,c and Figure 3d,e show the shape of the AFM tip reconstructed from nc-AFM

Nano-contact microscopy of supracrystals

• Adam Sweetman,
• Nicolas Goubet,
• Ioannis Lekkas,
• Marie Paule Pileni and
• Philip Moriarty

Beilstein J. Nanotechnol. 2015, 6, 1229–1236, doi:10.3762/bjnano.6.126

• intra-nanocrystal features is challenging for a number of reasons. First, the exact nature of our tip apex is unknown, and very possibly terminated either by free thiol ligands or entire nanocrystals. Second, due to the high aspect ratio of the nanocrystal surface (as compared to an atomically flat

• found that the evolution in contrast from STM, to constant Δf DFM, to constant height DFM was reproducible if we used different tip apices (prepared via gentle crashing into the sample). Figure 2A–C shows a dSTM, constant Δf DFM, and constant height DFM image all acquired using a different tip apex over

• , maintaining the same tip–sample separation. Repeating the force–distance measurements (Figure 2E), we observed a slight modification to the tip–sample force profiles, although we cannot rule out that the reduced peak force could also arise from a minor change in the tip apex. More striking was the observation

Automatic morphological characterization of nanobubbles with a novel image segmentation method and its application in the study of nanobubble coalescence

• Yuliang Wang,
• Huimin Wang,
• Shusheng Bi and
• Bin Guo

Beilstein J. Nanotechnol. 2015, 6, 952–963, doi:10.3762/bjnano.6.98

• contact angle θ for NB imaging is much larger than (90° + αtip), one can assume the NBs are probed only at the spherical tip apex and the side wall of the tip does not touch the NBs. The measured radius of curvature, R′, is given as R′ = R + Rtip, where Rtip (8 nm in this case) is the radius of curvature

Graphene on SiC(0001) inspected by dynamic atomic force microscopy at room temperature

• Mykola Telychko,
• Jan Berger,
• Zsolt Majzik,
• Pavel Jelínek and
• Martin Švec

Beilstein J. Nanotechnol. 2015, 6, 901–906, doi:10.3762/bjnano.6.93

• sample tilt. The reason to use current as a feedback, as opposed to using the frequency shift (Δf), is the possibility of doing measurements in the region of a negative frequency shift gradient (repulsive regime), even at room temperature, without enhanced risk of losing the tip apex. This approach is

Stick–slip behaviour on Au(111) with adsorption of copper and sulfate

• Nikolay Podgaynyy,
• Sabine Wezisla,
• Christoph Molls,
• Shahid Iqbal and
• Helmut Baltruschat

Beilstein J. Nanotechnol. 2015, 6, 820–830, doi:10.3762/bjnano.6.85

• structures. We assume that the tip apex is mobile enough in order to have a small variation in direction perpendicular to the tip motion. Black dotted lines on the Figure 8b show the path of tip apex while the red arrows represent the cantilever motion in scan direction. For a single jump, an average value

Boosting the local anodic oxidation of silicon through carbon nanofiber atomic force microscopy probes

• Gemma Rius,
• Matteo Lorenzoni,
• Soichiro Matsui,
• Masaki Tanemura and
• Francesc Perez-Murano

Beilstein J. Nanotechnol. 2015, 6, 215–222, doi:10.3762/bjnano.6.20

• tip apex of AFM probes for the application of LAO on silicon substrates in the AFM amplitude modulation dynamic mode of operation. We show the good performance of CNF-AFM probes in terms of resolution and reproducibility, as well as demonstration that the CNF apex provides enhanced conditions in terms

• control upon making CNT probes, as well as characteristic tip-to-tip differences, such as length, diameter, and operational complications, such as CNT buckling [15][16]. In this work, we explore the use of a carbon nanofiber (CNF) as the tip apex of AFM probes for the application of LAO-AFM on silicon

• to bare Si tip apex are the two mechanisms that would explain the boost in efficiency of CNF for LAO-AFM on silicon. The combination of an increased oxidation rate and an improvement in patterning resolution provided by the geometry of the CNF makes CNF-AFM probes very promising for further

Localized surface plasmon resonances in nanostructures to enhance nonlinear vibrational spectroscopies: towards an astonishing molecular sensitivity

• Dan Lis and
• Francesca Cecchet

Beilstein J. Nanotechnol. 2014, 5, 2275–2292, doi:10.3762/bjnano.5.237

• alternative technique, namely the tip-enhanced CARS microscopy, which exploits the confined excitation of a LSPR in the extremity of a metallic tip apex to map the surface, as it is done in near-field scanning optical microscopy. This enabled to move the source of the surface-enhanced field at any place of

Modification of a single-molecule AFM probe with highly defined surface functionality

• Fei Long,
• Bin Cao,
• Ashok Khanal,
• Shiyue Fang and
• Reza Shahbazian-Yassar

Beilstein J. Nanotechnol. 2014, 5, 2122–2128, doi:10.3762/bjnano.5.221

• a single-molecule probe [16]. They applied a bias voltage between an oligo(ethylene glycol) (OEG)-modified AFM probe and an Au film substrate. Carboxylic acid groups were selectively generated at the tip apex through electrochemical oxidation of OEG. The carboxylic acid group was then used to attach

• . Three control experiments were carried out to confirm that the ‘click’ reaction indeed occurred at the tip apex of the probes. In these experiments, one of the three components in the ‘click’ reaction (1) the alkyne on the probe, (2) the azide/carboxylic acid bi-functional molecule in the solution, and

Patterning a hydrogen-bonded molecular monolayer with a hand-controlled scanning probe microscope

• Matthew F. B. Green,
• Taner Esat,
• Christian Wagner,
• Philipp Leinen,
• Alexander Grötsch,
• F. Stefan Tautz and
• Ruslan Temirov

Beilstein J. Nanotechnol. 2014, 5, 1926–1932, doi:10.3762/bjnano.5.203

• be neglected (as for a point-like particle) such that the state of the particle is fully described by its three spatial coordinates. Since the position of the tip apex is also defined by a set of three coordinates, the full state space of an SPM junction that contains one point-like particle

• found in the Supporting Information). If the state of the tip apex was changed during HCM it was reshaped by gentle dipping into the surface. With this approach and without any prior experience it took about 40 minutes to remove the first molecule from the layer. Repeating the experiment, we observed

The optimal shape of elastomer mushroom-like fibers for high and robust adhesion

• Burak Aksak,
• Korhan Sahin and
• Metin Sitti

Beilstein J. Nanotechnol. 2014, 5, 630–638, doi:10.3762/bjnano.5.74

• effect of tip apex shape and friction, a model to estimate pull-off stress for mushroom-like fibers, and a comparison between cylindrical and mushroom-like fibers in terms of pull-off stress are discussed. Cohesive zone model Adhesion problems can be studied by using a cohesive zone model such as the

• ranging from no friction to full friction between the fiber tip and the adhering surface. As shown in Supporting Information File 1 (Figure S1), the magnitude of singular stress at the vicinity of the tip apex is higher for full friction interfaces than frictionless interfaces. Additionally, the limit

• finds χ = 33.6 and in turn e = 38. This estimate is close to e = 40 that del Campo et al. [21] obtained in their measurements. The implications tip apex shape on pull-off stress The manufacturing technique used to fabricate mushroom-like fibers may not yield a sharp corner (i.e., wedge) for individual

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

• ‘off’ measurements are, in principle, available [6][11]. In this paper we perform a simple set of force measurements using the same tip apex on two different surface locations where we are able to use the ‘on-minus-off’ method. This is done by depositing C60 molecules onto a clean Si(111)-(7 × 7

• ’ method shows a weak attractive force between tip and sample, suggesting either a molecular or weakly interacting silicon tip apex [23] which does not form a strong covalent bond with the molecule. Examining the short-range forces extracted by long-range extrapolation, fitting to the 'off' curve (Figure

• we are clearly attempting to fit part of the short-range interaction, present in the on curve, using the power law. With respect to the tip–silicon results (Figure 2C and Figure 2D), the force profiles from ‘on-minus-off’ are consistent with chemical bond formation between the tip apex and the

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

• carboxylic oxygen atoms attached at the four corners of the rectangular aromatic backbone. Approaching the metal tip to one of the carboxylic oxygen atoms, it is possible to form a local chemical bond between the oxygen and the outermost atom of the tip apex [23]. This bond is of sufficient mechanical

• = 1.3 eV, r0 = 2.2 Å, a = 2.0 Å−1) binding one of the carboxylic oxygens to the outermost tip apex atom. The parameters of this potential have been determined with the help of DFT simulations presented in [23]. The molecule–surface interaction is described as a set of individual atom–surface potentials

• model further, we allow for a finite stiffness of the tip that is simulated by introducing an additional atom situated above the tip apex atom and connected to it via a harmonic 1D potential (cf. inset Figure 2a). The stiffness ktip of this harmonic bond is fixed, but the bond itself is allowed to relax

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

• molecule A as well as for molecule B. Previous ab-initio simulations of PTCDA on Ag(111) predict a slight asymmetry of the end groups in the dissipation channel at small distances [17], but only for one molecular orientation. Therefore we speculate that this effect is related to an asymmetry of the tip

• apex in this experiment [18]. This onset can be determined more accurately based on a comparison of the FTS(z) curves for both molecule orientations. The corresponding curves, which are averaged for the perylene cores (left) and the complete molecules (right), are shown in Figure 5. The deviations

Structural development and energy dissipation in simulated silicon apices

• Samuel Paul Jarvis,
• Lev Kantorovich and
• Philip Moriarty

Beilstein J. Nanotechnol. 2013, 4, 941–948, doi:10.3762/bjnano.4.106

• structural evolution of the tip apex within a low temperature NC-AFM experiment, we simulated a repeated tip–surface indentation until the tip structure converged to a stable termination and the characteristic hysteretic behaviour was no longer observed. Our calculations suggest that varying just a single

• ]. Moreover, atomistic simulations remain essential to many current studies in covalent [17][18][19] and ionic [20][21] systems because of the inherent difficulties in determining the tip apex structure from purely experimental evidence. In contrast, on metal surfaces the requirement to use atomistic

• metallic tip apex by using the so-called carbon oxide front atom identification method (COFI) [22]. Such techniques provide an intuitive way in which to analyse and prepare the scanning probe tip. Similarly, reverse imaging can be employed on semiconductor surfaces, such as Si(111)-7×7 [23][24]. A

k-space imaging of the eigenmodes of sharp gold tapers for scanning near-field optical microscopy

• Martin Esmann,
• Simon F. Becker,
• Bernard B. da Cunha,
• Jens H. Brauer,
• Ralf Vogelgesang,
• Petra Groß and
• Christoph Lienau

Beilstein J. Nanotechnol. 2013, 4, 603–610, doi:10.3762/bjnano.4.67

• propagating along the taper. This far-field coupling can occur within the last micron from the tip apex, making it difficult to distinguish these modes from the nano-localized LSP fields. This hampers efficient background-free nanofocusing with the setup described in [10] and higher order mode suppression

• importantly, it allows us to probe the near-field coupling between the tip dipole, i.e., the near fields at the tip apex, and its image dipole induced in the metal (see [21][22]). The light transmitted through the gold-coated cover slip is collected using an oil immersion objective with high numerical

• aperture (NA = 1.3, Olympus UPlanFLN 100×). The tip-apex position lies within the focal plane of the microscope objective. In this configuration, the objective performs a Fourier transform of the field distribution from the front into the back focal plane. Two additional lenses with focal lengths of f1

Apertureless scanning near-field optical microscopy of sparsely labeled tobacco mosaic viruses and the intermediate filament desmin

• Alexander Harder,
• Mareike Dieding,
• Volker Walhorn,
• Sven Degenhard,
• Andreas Brodehl,
• Christina Wege,
• Hendrik Milting and
• Dario Anselmetti

Beilstein J. Nanotechnol. 2013, 4, 510–516, doi:10.3762/bjnano.4.60

• illuminated AFM cantilever tip apex exposes strongly confined non-propagating electromagnetic fields that can serve as a coupling agent for single dye molecules. Thus, combining both techniques by means of apertureless scanning near-field optical microscopy (aSNOM) enables concurrent high resolution

• topography and fluorescence imaging. Commonly, among the various (apertureless) SNOM approaches metallic or metallized probes are used. Here, we report on our custom-built aSNOM setup, which uses commercially available monolithic silicon AFM cantilevers. The field enhancement confined to the tip apex

• ; fluorescence microscopy; Introduction Scanning near-field optical microscopy (SNOM) provides sub-wavelength optical resolution [1]. The sample is excited by the strongly confined near-field at the tip apex, which is induced by the dipolar coupling between the incident light and the probe. Moreover, coupling