High-resolution dynamic atomic force microscopy in liquids with different feedback architectures

• John Melcher,
• David Martínez-Martín,
• Miriam Jaafar,
• Julio Gómez-Herrero and
• Arvind Raman

Beilstein J. Nanotechnol. 2013, 4, 153–163, doi:10.3762/bjnano.4.15

• forces can be remarkable similar. Furthermore, the reduction in noncontact forces and quality factors in liquids diminishes the role of feedback control in achieving high-resolution images. The theoretical findings are supported by atomic-resolution images of mica in water acquired with AM, FM and DAM

• ), noncontact regime when d is sufficiently large, which gives way to a repulsive (∂Fts/∂d < 0), contact regime as d is reduced. If k < ∂Fts/∂d, then for some z, x* will be bistable. This results in one stable equilibrium for both the noncontact and contact regimes. In this case, a spontaneous transition from

• the noncontact equilibrium to the contact equilibrium, or snap-in, can occur [20]. The snap-in instability is avoided if the equilibrium deflection is monostable, which occurs when either z is sufficiently large for a given k or when k exceeds the maximum gradient of Fts [10][21]. The model for the

Effect of normal load and roughness on the nanoscale friction coefficient in the elastic and plastic contact regime

• Aditya Kumar,
• Thorsten Staedler and
• Xin Jiang

Beilstein J. Nanotechnol. 2013, 4, 66–71, doi:10.3762/bjnano.4.7

• vapor deposition (Balzer BAS 450) utilizing a gas mixture of argon and acetylene at a bias voltage of −950 and −350 V, respectively. Topographical characterization: The surface morphology was characterized by atomic force microscopy (AFM, Park Systems Corp. XE-100). Noncontact AFM was used to obtain

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

• : SmarAct GmbH, Schütte-Lanz-Strasse 9, 26135 Oldenburg, Germany now at: Department of Physics and Astronomy, The University of Utah, 115 South 1400 East, Salt Lake City, UT 84112, USA 10.3762/bjnano.4.4 Abstract The noise of the frequency-shift signal Δf in noncontact atomic force microscopy (NC-AFM

• system with a low-noise signal detection and a suitable cantilever, operated with appropriate filter and feedback-loop settings allows room temperature NC-AFM measurements at a low thermal-noise limit with a significant bandwidth. Keywords: Cantilever; feedback loop; filter; noncontact atomic force

• microscopy (NC-AFM); noise; Introduction In this contribution, we discuss noise in frequency-modulation noncontact atomic force microscopy (NC-AFM) using cantilevers as force sensors and optical beam deflection (OBD) for signal detection. Figure 1 shows a schematic diagram of an NC-AFM setup based on OBD to

Calculation of the effect of tip geometry on noncontact atomic force microscopy using a qPlus sensor

• Julian Stirling and
• Gordon A. Shaw

Beilstein J. Nanotechnol. 2013, 4, 10–19, doi:10.3762/bjnano.4.2

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

• , including biology, chemistry and physics. In particular, noncontact atomic force microscopy [3] (nc-AFM) has developed into a powerful technique for imaging with true atomic resolution [4][5], chemical sensitivity [6][7][8] or for performing single atom manipulation [9][10][11] on all types of surfaces

• sensitivity to the tunneling current signal comparing to traditional Si cantilevers. This new approach opens new possibilities in the characterization of surfaces and nanostructures on the atomic scale (see, e.g., [16]). Not surprisingly, qPlus sensors have become frequently used for noncontact measurements

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

• resolution was first achieved in the 1990s. The most convincing results, however, were restricted to the so-called noncontact mode in vacuum for a long time, but recent technical developments overcame this limitation, and atomic-resolution imaging is now also a standard in liquids. Beyond pushing the

• fields, and the imaging and discrimination of individual chemical bonds. The development of advanced techniques is the focus of this Thematic Series, following the Thematic Series “Scanning probe microscopy and related techniques” edited by Ernst Meyer and the Thematic Series “Noncontact atomic force

Spring constant of a tuning-fork sensor for dynamic force microscopy

• Dennis van Vörden,
• Manfred Lange,
• Merlin Schmuck,
• Nico Schmidt and
• Rolf Möller

Beilstein J. Nanotechnol. 2012, 3, 809–816, doi:10.3762/bjnano.3.90

• configuration is given by Hooke’s law F = −kz, with the spring constant k and the deflection z. For the experiment, the TFs are glued to a holder in exactly the same way as for the low-temperature noncontact AFM developed in our group [25]. To apply a force on the TF a loop is formed by a thin wire, which is

Probing three-dimensional surface force fields with atomic resolution: Measurement strategies, limitations, and artifact reduction

• Mehmet Z. Baykara,
• Omur E. Dagdeviren,
• Todd C. Schwendemann,
• Harry Mönig,
• Eric I. Altman and
• Udo D. Schwarz

Beilstein J. Nanotechnol. 2012, 3, 637–650, doi:10.3762/bjnano.3.73

• , Germany Department of Chemical and Environmental Engineering, Yale University, New Haven, CT 06520, USA 10.3762/bjnano.3.73 Abstract Noncontact atomic force microscopy (NC-AFM) is being increasingly used to measure the interaction force between an atomically sharp probe tip and surfaces of interest, as a

• fields, including catalysis, thin-film growth, nanoscale device fabrication, and tribology, among others [1]. Shortly after the first atomic-resolution images of surfaces were obtained by noncontact atomic force microscopy (NC-AFM) [2][3], the method of dynamic force spectroscopy (DFS) was introduced

Focused electron beam induced deposition: A perspective

• Michael Huth,
• Fabrizio Porrati,
• Christian Schwalb,
• Marcel Winhold,
• Roland Sachser,
• Maja Dukic,
• Jonathan Adams and
• Georg Fantner

Beilstein J. Nanotechnol. 2012, 3, 597–619, doi:10.3762/bjnano.3.70

Nanostructures for sensors, electronics, energy and environment

• Nunzio Motta

Beilstein J. Nanotechnol. 2012, 3, 351–352, doi:10.3762/bjnano.3.40

• ” edited by Ernst Meyer [6] and “Noncontact atomic force microscopy” edited by Udo Schwarz [7] to which the interested reader is directed for more information. Science always holds surprises, and I am delighted to present this Thematic Series, giving a quick glance at the science and application of

Drive-amplitude-modulation atomic force microscopy: From vacuum to liquids

• Miriam Jaafar,
• David Martínez-Martín,
• Mariano Cuenca,
• John Melcher,
• Arvind Raman and
• Julio Gómez-Herrero

Beilstein J. Nanotechnol. 2012, 3, 336–344, doi:10.3762/bjnano.3.38

• environments. Drive-amplutide modulation is a very stable, intuitive and easy to use mode that is free of the feedback instability associated with the noncontact-to-contact transition that occurs in the frequency-modulation mode. Keywords: atomic force microscopy; control systems; dissipation; frequency

• modulation; noncontact; Introduction Dynamic atomic force microscopy (dAFM) [1][2] is a powerful yet versatile tool capable of operating in environments ranging from ultrahigh vacuum (UHV) to liquids [3][4], and imaging samples ranging from stiff inorganic materials [5] to soft biological matter [6], with

• high quality factor Q of the cantilevers in vacuum, which present a settling time given by τcl= Q/(πf0). Frequency-modulation AFM (FM-AFM, also known as noncontact AFM) [9] is the classical alternative to AM allowing atomic resolution in UHV chambers [10] at higher scanning rates. FM-AFM has recently

Models of the interaction of metal tips with insulating surfaces

• Thomas Trevethan,
• Matthew Watkins and
• Alexander L. Shluger

Beilstein J. Nanotechnol. 2012, 3, 329–335, doi:10.3762/bjnano.3.37

• . Keywords: atomic force microscopy; density functional theory; ionic surfaces; metallic asperities; surface interactions; Introduction The noncontact atomic force microscope (NC-AFM) is capable of imaging both conducting and insulating systems with true atomic resolution and has provided extraordinary

• . In each case it is clear that the force is largest directly above anions in the surface, significantly so in the range probed by noncontact imaging, i.e., 3–5 Å. For each tip above an anion in the surface, at close approach (approx. 3–4 Å) the force increases markedly due to a structural change

• functions were fitted to these energies as a function of tip height for each position, in the noncontact range of 4–7 Å, where no instabilities occur. The derivative of this function gives the force on the tip due to the interaction with the surface, as a function of tip height, which is shown in Figure 6

Nano-FTIR chemical mapping of minerals in biological materials

• Sergiu Amarie,
• Paul Zaslansky,
• Yusuke Kajihara,
• Erika Griesshaber,
• Wolfgang W. Schmahl and
• Fritz Keilmann

Beilstein J. Nanotechnol. 2012, 3, 312–323, doi:10.3762/bjnano.3.35

• . Intricate carbonate-based natural skeletons, that may include transient and stabilized amorphous phases, can now be mapped within and across interfaces by a noncontact and nondestructive imaging technique. With respect to apatite studies, our method is directly applicable to the investigation of healthy and

Graphite, graphene on SiC, and graphene nanoribbons: Calculated images with a numerical FM-AFM

• Fabien Castanié,
• Laurent Nony,
• Sébastien Gauthier and
• Xavier Bouju

Beilstein J. Nanotechnol. 2012, 3, 301–311, doi:10.3762/bjnano.3.34

• points (yellow-red) due to the reduction of the tip–atom surface distance. Moreover, one can easily distinguish the long edges, which are two rows of C atoms higher than the narrow ones. The 6 × 6 periodicity was observed in noncontact mode AFM [111] but with smoother edges obtained in the constant

Wavelet cross-correlation and phase analysis of a free cantilever subjected to band excitation

• Francesco Banfi and
• Gabriele Ferrini

Beilstein J. Nanotechnol. 2012, 3, 294–300, doi:10.3762/bjnano.3.33

• disciplines, but it is not widespread in the context of noncontact AFM. This may be due to the absence of discussions of the practical and technical aspects of wavelet analysis relating to noncontact AFM. This article shows the use of wavelet cross-correlation by means of two simple but paradigmatic examples

Dipole-driven self-organization of zwitterionic molecules on alkali halide surfaces

• Laurent Nony,
• Franck Bocquet,
• Franck Para,
• Frédéric Chérioux,
• Eric Duverger,
• Frank Palmino,
• Vincent Luzet and
• Christian Loppacher

Beilstein J. Nanotechnol. 2012, 3, 285–293, doi:10.3762/bjnano.3.32

• -ST, Université de Franche-Comté, CNRS, ENSMM, 32, Avenue de l’Observatoire, F-25044 Besancon Cedex, France 10.3762/bjnano.3.32 Abstract We investigated the adsorption of 4-methoxy-4′-(3-sulfonatopropyl)stilbazolium (MSPS) on different ionic (001) crystal surfaces by means of noncontact atomic force

• step edges decorated with MSPS molecules that run along the <110> direction. These polar steps most probably minimize the surface energy as they counterbalance the molecular dipole by presenting oppositely charged ions on the rearranged step edge. Keywords: alkali halide surface; noncontact atomic

• of the substrate to ≈110 °C for 15–30 min. Annealing to lower temperatures only affected the substrate surface a little; choosing higher temperatures resulted in desorption of the molecules. Noncontact atomic force microscopy (NC-AFM) measurements were performed in situ under UHV conditions (<2·10−10

Modeling noncontact atomic force microscopy resolution on corrugated surfaces

• Kristen M. Burson,
• Mahito Yamamoto and
• William G. Cullen

Beilstein J. Nanotechnol. 2012, 3, 230–237, doi:10.3762/bjnano.3.26

• specific case. We develop a quasi-1-D minimal model for noncontact atomic force microscopy, based on van der Waals interactions between a spherical tip and the surface, explicitly accounting for the corrugated substrate (modeled as a sinusoid). The model results show an attenuation of the topographic

• contours by ~30% for tip distances within 5 Å of the surface. Results also indicate a deviation from the Hamaker force law for a sphere interacting with a flat surface. Keywords: graphene; model; noncontact atomic force microscopy; SiO2; van der Waals; Introduction Noncontact atomic force microscopy (NC

An NC-AFM and KPFM study of the adsorption of a triphenylene derivative on KBr(001)

• Antoine Hinaut,
• Adeline Pujol,
• Florian Chaumeton,
• David Martrou,
• André Gourdon and
• Sébastien Gauthier

Beilstein J. Nanotechnol. 2012, 3, 221–229, doi:10.3762/bjnano.3.25

• designed molecule, consisting of a flat aromatic triphenylene core equipped with six flexible propyl chains ending with polar cyano groups, is investigated by using atomic force microscopy in the noncontact mode (NC-AFM) coupled to Kelvin probe force microscopy (KPFM) in ultrahigh vacuum at room

• the development of atomic force microscopy in the noncontact (or frequency modulation) mode [1][2][3][4][5][6][7][8][9][10][11][12][13]. A wide variety of structures, from 3-D islands to single molecules have been observed on different surfaces with an ever-increasing resolution, and there is still

A measurement of the hysteresis loop in force-spectroscopy curves using a tuning-fork atomic force microscope

• Manfred Lange,
• Dennis van Vörden and
• Rolf Möller

Beilstein J. Nanotechnol. 2012, 3, 207–212, doi:10.3762/bjnano.3.23

• Manfred Lange Dennis van Vorden Rolf Moller Faculty of Physics, University of Duisburg-Essen, Lotharstr.1-21 47048 Duisburg, Germany 10.3762/bjnano.3.23 Abstract Measurements of the frequency shift versus distance in noncontact atomic force microscopy (NC-AFM) allow measurements of the force

• about 0.22 eV/cycle. Keywords: atomic force microscopy; energy dissipation; force spectroscopy; hysteresis loop; PTCDA/Ag/Si(111) √3 × √3; Introduction Noncontact atomic force microscopy (NC-AFM) is a powerful tool for the study of surface properties. The invention of the frequency-modulation mode (FM

Noncontact atomic force microscopy study of the spinel MgAl₂O₄(111) surface

• Morten K. Rasmussen,
• Kristoffer Meinander,
• Flemming Besenbacher and
• Jeppe V. Lauritsen

Beilstein J. Nanotechnol. 2012, 3, 192–197, doi:10.3762/bjnano.3.21

• Morten K. Rasmussen Kristoffer Meinander Flemming Besenbacher Jeppe V. Lauritsen Interdisciplinary Nanoscience Center and Department of Physics and Astronomy, Aarhus University, Ny Munkegade, DK-8000 Aarhus C, Denmark 10.3762/bjnano.3.21 Abstract Based on high-resolution noncontact atomic force

• distinct pattern of line vacancies reflected by the underlying lattice structure. Consequently, by the creation of triangular patches in a 6√3×6√3R30° superstructure, the polar-stabilization requirements are met. Keywords: aluminium oxide; metal oxide surfaces; noncontact atomic force microscopy (NC-AFM

• and in particular a direct atomic-scale characterization of the surface structure is largely missing for a range of important metal oxides. In recent years, the noncontact atomic force microscope (NC-AFM) has been established as a unique tool to provide atomic-resolution real-space images of all types

Quantitative multichannel NC-AFM data analysis of graphene growth on SiC(0001)

• Christian Held,
• Thomas Seyller and
• Roland Bennewitz

Beilstein J. Nanotechnol. 2012, 3, 179–185, doi:10.3762/bjnano.3.19

• Christian Held Thomas Seyller Roland Bennewitz INM – Leibniz-Institute for New Materials, Campus D2 2, 66123 Saarbrücken, Germany Lehrstuhl für Technische Physik, Universität Erlangen-Nürnberg, 91058 Erlangen, Germany 10.3762/bjnano.3.19 Abstract Noncontact atomic force microscopy provides access

• almost the same carbon density as one layer of graphene [16]. Experimental Noncontact atomic force microscopy (NC-AFM) measurements were performed in ultrahigh vacuum (UHV, p < 2·10−10 mbar) by means of a home-built microscope similar to the one described in [17]. Kelvin probe force microscopy (KPFM

• around 100 kHz. This choice of cantilever gives the opportunity to perform complementary contact-mode friction and noncontact KPFM experiments on the same surface areas [20]. Graphene grown in UHV The substrate material for the study is the Si face of 6H-SiC(0001). The unit cell of 6H-SiC is composed of

Noncontact atomic force microscopy

• Udo D. Schwarz

Beilstein J. Nanotechnol. 2012, 3, 172–173, doi:10.3762/bjnano.3.17

• if it is not allowed to touch? This problem was solved in the 1990s through the realization that the attractive forces acting on the tip when it is in close proximity to the sample affect the resonance frequency of the cantilever even though it is not in actual contact with the surface. Noncontact

Effect of the tip state during qPlus noncontact atomic force microscopy of Si(100) at 5 K: Probing the probe

• Adam Sweetman,
• Sam Jarvis,
• Rosanna Danza and
• Philip Moriarty

Beilstein J. Nanotechnol. 2012, 3, 25–32, doi:10.3762/bjnano.3.3

• Adam Sweetman Sam Jarvis Rosanna Danza Philip Moriarty School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, U.K. 10.3762/bjnano.3.3 Abstract Background: Noncontact atomic force microscopy (NC-AFM) now regularly produces atomic-resolution images on a wide range of

• functionalised tips has provided additional impetus to elucidating the role of the tip apex in the observed contrast. Results: We present an analysis of the influence of the tip apex during imaging of the Si(100) substrate in ultra-high vacuum (UHV) at 5 K using a qPlus sensor for noncontact atomic force

• ; noncontact AFM; qPlus; Si(001); Si(100); tip (apex) structure; Introduction It is now generally accepted that atomic resolution in NC-AFM imaging on semiconducting surfaces is due to the chemical force between the atoms of the surface and the last few atoms of the tip apex [1][2][3][4]. Even with well