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

• 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

• constants of ≈50 N/m, and quality factors of ≈35,000. Typical oscillation amplitudes were 5–10 nm (10–20 nm peak-to-peak). The cantilevers were heated in situ to ≈150 °C for one hour in order to remove contaminants from the tip. In NC-AFM, the oscillation amplitude of the cantilever is kept constant by an

• -like cis (a) and the scorpion-like trans (b) isomerization. 0.2 ML of MSPS evaporated onto KCl. (a) displays the NC-AFM topography after deposition at RT (Δf = −59 Hz, A0 = 7 nm), (b) shows the surface after annealing to 110 °C for 15 min (Δf = −40 Hz, A0 = 7 nm). The substrate orientation is shown in

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

• /bjnano.3.26 Abstract Key developments in NC-AFM have generally involved atomically flat crystalline surfaces. However, many surfaces of technological interest are not atomically flat. We discuss the experimental difficulties in obtaining high-resolution images of rough surfaces, with amorphous SiO2 as a

• with the energetics of substrate adhesion [11][12][13]. Our previous work [14] addressed the issue of intrinsic rippling in SiO2-supported graphene by presenting high-resolution UHV NC-AFM measurements of the SiO2, in which it was shown that there were more small-scale features present on the SiO2 than

• contrast, for corrugated surfaces, the vdW interactions will vary laterally and thus play a greater role in determining the contour followed by the probe tip. These experimental observations highlight the difficulty in obtaining adequately resolved NC-AFM measurements on rough, amorphous surfaces and

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

• combined with NC-AFM [16][17][18][19] to investigate metallic or semiconducting surfaces, as well as adsorbates [20][21] or thin insulating films on metals [18][22][23]. But its application to bulk insulating surfaces [24][25][26] is only beginning, and studies of molecular adsorption on these surfaces are

• first results of a coupled NC-AFM and KPFM study of the adsorption on KBr(001) of 2,3,6,7,10,11-hexa(cyanopropyloxy)triphenylene (HCPTP), presented in Figure 1. This molecule was designed to adsorb strongly on an alkali halide surface in the hope of blocking its diffusion at room temperature. It is

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

• process can be understood as a hysteresis of forces between approach and retraction of the tip. In this paper, we present the direct measurement of the whole hysteresis loop in force-spectroscopy curves at 77 K on the PTCDA/Ag/Si(111) √3 × √3 surface by means of a tuning-fork-based NC-AFM with an

• 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

• microscopy (NC-AFM) experiments we reveal a detailed structural model of the polar (111) surface of the insulating ternary metal oxide, MgAl2O4 (spinel). NC-AFM images reveal a 6√3×6√3R30° superstructure on the surface consisting of patches with the original oxygen-terminated MgAl2O4(111) surface interrupted

• 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

• representation of multichannel NC-AFM data sets in a quantitative fashion. Presentation and analysis are exemplified for topography and contact-potential data for graphene grown epitaxially on 6H-SiC(0001), as recorded by Kelvin probe force microscopy in ultrahigh vacuum. Sample preparations by thermal

• 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

• , the surface was imaged by NC-AFM (Figure 1a). Flat terraces with a typical width of 500 nm were found. The surface of terraces is covered with irregular mounds of up to 0.5 nm in height. Smaller depressed islands decorate the steps between terraces (see white arrow in Figure 1a). The steps between

Noncontact atomic force microscopy

• Udo D. Schwarz

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

• atomic force microscopy (NC-AFM) makes use of this effect by tracking the shift of the cantilever resonance frequency due to the force field of the surface without ever establishing physical contact between the tip and sample. Much to the astonishment of many, changes induced by individual atoms turned

• out to induce frequency shifts that are large enough to be detected, and thus atomic-scale imaging with AFM became a reality. Since the beginnings, almost two decades ago, NC-AFM has evolved into a powerful method that is able not just to image surfaces, but also to quantify tip–sample forces and

• conference from this series was held in Lindau, Germany, from September 18–22, 2011. Once again, substantial progress was presented; NC-AFM is now able to quantitatively map three-dimensional force fields of surfaces with atomic resolution in ultrahigh vacuum as well as in liquids, and methodological

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

• microscopy (NC-AFM). Data demonstrating stable imaging with a range of tip apexes, each with a characteristic imaging signature, have been acquired. By imaging at close to zero applied bias we eliminate the influence of tunnel current on the force between tip and surface, and also the tunnel-current-induced

• a valuable resource for theoreticians working on the development of realistic tip structures for NC-AFM simulations. Force spectroscopy measurements show that the tip termination critically affects both the short-range force and dissipated energy. Keywords: force spectroscopy; image contrast

Manipulation of gold colloidal nanoparticles with atomic force microscopy in dynamic mode: influence of particle–substrate chemistry and morphology, and of operating conditions

• Samer Darwich,
• Karine Mougin,
• Akshata Rao,
• Enrico Gnecco,
• Shrisudersan Jayaraman and
• Hamidou Haidara

Beilstein J. Nanotechnol. 2011, 2, 85–98, doi:10.3762/bjnano.2.10

• , the applicability of contact AFM to nanomanipulation was limited to relatively large objects (tens of nanometers in size). The latest results obtained by Custance et al. show that it is now possible to manipulate single atoms using NC-AFM [12]. Byungsoo Kim et al. [13] have also proposed a new

• tip's oscillation amplitude (NC-AFM). We have also performed measurements in contact mode, where the set point is determined by the normal load acting between tip and sample. PPP-NCLR and CONT cantilevers from Nanosensors were used in both cases. Evolution of the logarithm of the dissipated power

Oriented growth of porphyrin-based molecular wires on ionic crystals analysed by nc-AFM

• Thilo Glatzel,
• Lars Zimmerli,
• Shigeki Kawai,
• Ernst Meyer,
• Leslie-Anne Fendt and
• Francois Diederich

Beilstein J. Nanotechnol. 2011, 2, 34–39, doi:10.3762/bjnano.2.4

• molecular assemblies can be formed. The electronic decoupling of the molecules by one or two monolayers of KBr from the Cu(111) substrate is found to be insufficient to enable comparable growth conditions to bulk ionic materials. Keywords: directed growth; KBr; molecular wires; NaCl; nc-AFM; porphyrin

• studies by non-contact atomic force microscopy (nc-AFM) were done on ionic crystals with adsorbed PTCDA [17][18][19][20][21][22], PTCDI [23] or C60 [24]. In the case of porphyrins, the growth [25][26][27] and electronic properties [28] of stable, monolayered molecular wires on KBr(001) with a length of up

• measurements of molecules on insulating surfaces were scarce due to a lack of suitable imaging techniques. However, recent progress in high resolution nc-AFM has given the opportunity to verify the proposed concept of directed growth of molecular wires on insulators [31][32][33]. Alkali halides offer some

Defects in oxide surfaces studied by atomic force and scanning tunneling microscopy

• Thomas König,
• Georg H. Simon,
• Lars Heinke,
• Leonid Lichtenstein and
• Markus Heyde

Beilstein J. Nanotechnol. 2011, 2, 1–14, doi:10.3762/bjnano.2.1

• Thomas Konig Georg H. Simon Lars Heinke Leonid Lichtenstein Markus Heyde Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany 10.3762/bjnano.2.1 Abstract Surfaces of thin oxide films were investigated by means of a dual mode NC-AFM/STM. Apart from imaging the

• surface termination by NC-AFM with atomic resolution, point defects in magnesium oxide on Ag(001) and line defects in aluminum oxide on NiAl(110), respectively, were thoroughly studied. The contact potential was determined by Kelvin probe force microscopy (KPFM) and the electronic structure by scanning

• aluminum oxide. At these domain boundaries, STS and KPFM verify F2+-like centers, which have been predicted by density functional theory calculations. Thus, by determining the contact potential and the electronic structure with a spatial resolution in the nanometer range, NC-AFM and STM can be successfully

Tip-sample interactions on graphite studied using the wavelet transform

• Giovanna Malegori and
• Gabriele Ferrini

Beilstein J. Nanotechnol. 2010, 1, 172–181, doi:10.3762/bjnano.1.21

• microscopy (NC-AFM) is a powerful tool to study not only the surface topography, but also the mechanical and chemical characteristics of the sample at the nanoscale [1][2][3]. The tip of an excited cantilever is sensitive to both forces and force gradients, when approaching the sample surface. The response

Scanning probe microscopy and related methods

• Ernst Meyer

Beilstein J. Nanotechnol. 2010, 1, 155–157, doi:10.3762/bjnano.1.18

• molecules on surfaces. AFM has evolved considerably in the last few years, where new operation modes, such as non-contact force microscopy (nc-AFM), Kelvin probe force microscopy (KPFM) or friction force microscopy (FFM), were developed. One main focus is the high resolution capabilities of nc-AFM, which

• were drastically improved. Atomic resolution on metals, semiconductors [3] and insulators was achieved. Recently, the atomic structure of single molecules was identified by nc-AFM, which gives new opportunities to investigate the local structure of these molecules [4]. In this Thematic Series, the

• structure of oxides is explored by the combination of nc-AFM. Colour centres are characterized by KPFM and tunnelling spectroscopy. The arrangement of molecules on insulators is another type of application, which is discussed in the present Thematic Series. The ability to measure across phase transitions