Optical properties and electrical transport of thin films of terbium(III) bis(phthalocyanine) on cobalt

• Peter Robaschik,
• Pablo F. Siles,
• Daniel Bülz,
• Peter Richter,
• Manuel Monecke,
• Michael Fronk,
• Svetlana Klyatskaya,
• Daniel Grimm,
• Oliver G. Schmidt,
• Mario Ruben,
• Dietrich R. T. Zahn and
• Georgeta Salvan

Beilstein J. Nanotechnol. 2014, 5, 2070–2078, doi:10.3762/bjnano.5.215

• TbPc2 thin films is crucial for future molecular spintronics applications. Experimental Sample preparation Cobalt films were grown by electron beam evaporation on a Si(111) substrate covered by a oxide layer with different thickness (VASE, AFM: 1.5 nm and cs-AFM: 1 µm) at a rate of 1.25 nm/min under UHV

• analyzed using WSxM and Gwyddion software packages [31][32]. TbPc2 molecule (left). Investigated layer stack: TbPc2 thin films on cobalt grown on SiO2/Si(111). Dielectric function of a TbPc2 film on cobalt. The blue lines and the red lines represent the real part (left) and the imaginary part (right

Probing the electronic transport on the reconstructed Au/Ge(001) surface

• Franciszek Krok,
• Mark R. Kaspers,
• Alexander M. Bernhart,
• Marek Nikiel,
• Benedykt R. Jany,
• Paulina Indyka,
• Mateusz Wojtaszek,
• Rolf Möller and
• Christian A. Bobisch

Beilstein J. Nanotechnol. 2014, 5, 1463–1471, doi:10.3762/bjnano.5.159

• other nanowire structures, e.g., in atoms on Si(111) [4] or Au on Si(557) [5], the Au/Ge(001) wires are rather robust against a Peierls distortion [6], so that the Au/Ge(001) surface offers the unique opportunity to study a Tomonaga–Luttinger liquid. In addition, such atomic scale wires may be used as

• . The mechanical stability and performance of the commercial STM setup was improved in order to provide atomic resolution, e.g., on the Si(111)-(7 × 7) surface or the Bi(111) surface [12]. During the scanning tunnelling potentiometry (STP) experiments, two tips contact the surface and drive a lateral

• surface transport in Si(111)-√3 × √3:Ag [13] and thin Bi(111) films on silicon [12][16] would be expected. However, the maps of the potential show no fine-structure related to the step edges or other surface defects so we conclude that the main current is not carried by the surface, i.e., the Au atomic

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

• procedure can be utilised for surface atoms if there is a large enough ‘empty’ region on a flat surface that does not exert any short-range force. A well-known example of this is the cornerhole on the Si(111)-(7 × 7) surface [2]. A cartoon of these two cases is shown in Figure 1B and Figure 1C. Although the

• ‘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

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

• 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

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

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

• be able to evaluate the physical magnitude of the oscillation amplitude, the conversion factor (C = Vth/Ath) needs to be determined. C was estimated during dynamic STM measurement on a clean Si(111)-(7 × 7) surface with a precision of ≈10%. It is worth noting that, as the amplitude Ath is represented

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

• (111) and Si(111)) with atomic steps of well-known height. Next, the amplitude of the TFs oscillation is varied, while simultaneous monitoring the change in height at constant tunneling current, and the electric signal is detected by the TF. The inset in Figure 4 displays the corresponding graph. This

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

• sample surface. Force fields have now been recorded on NiO(001) [10][12][13], MgO/Ag(001) [14], NaCl(001) [15][16], Si(111)-(7×7) [17][18][19], HOPG [20][21], KBr(001) [9][22][23], Cu(111) [24], and CaCO3() [25] surfaces, as well as single molecules of PTCDA [26][27], pentacene [28], CO [29], C60 [30

Synthesis and electrical characterization of intrinsic and in situ doped Si nanowires using a novel precursor

• Wolfgang Molnar,
• Alois Lugstein,
• Tomasz Wojcik,
• Peter Pongratz,
• Norbert Auner,
• Christian Bauch and
• Emmerich Bertagnolli

Beilstein J. Nanotechnol. 2012, 3, 564–569, doi:10.3762/bjnano.3.65

• with He as the feed gas. A more detailed description of the growth apparatus is given in [30]. As substrates, pieces of Si (111) were cleaned with acetone, rinsed with propan-2-ol and blown dry with N2. The native oxide was removed by buffered hydrofluoric acid (BHF; HF/NH4F 7:1) resulting in a

• investigations. The TEM image in Figure 2a shows a slightly tapered, intrinsic Si-NW with a catalytic particle atop. The HRTEM micrograph of the crystalline core in Figure 2b shows clearly the Si(111) atomic planes (separation 3.14 Å) perpendicular to the NW axis. The reciprocal lattice peaks in the diffraction

Directed deposition of silicon nanowires using neopentasilane as precursor and gold as catalyst

• Britta Kämpken,
• Verena Wulf,
• Norbert Auner,
• Marcel Winhold,
• Michael Huth,
• Daniel Rhinow and
• Andreas Terfort

Beilstein J. Nanotechnol. 2012, 3, 535–545, doi:10.3762/bjnano.3.62

• the silicon NWs. Results and Discussion Sputtered gold films as catalyst The first series of experiments was performed with Si[111] and borosilicate glass substrates. Borosilicate glass was used in this case to prove that the silicon in the grown nanowires originated from the precursor and not from

• nanoparticles with a size of 60 nm were synthesized by following standard protocols [42] and deposited from solution onto Si[111] substrates. For this, the native oxide layer of the silicon wafers was modified by a monolayer of 3-aminopropyl-terminated siloxane [43], the amino groups of which are able to

• layer of a Si[111] substrate. At 7000 rpm a dense coating was achieved in the form of a sticky film. Annealing of this film at 650 °C for 1 h in the presence of air resulted in dense but inhomogeneous gold particle coverage. Those particles partially resembled the nanoparticle assemblies obtained from

Simultaneous current, force and dissipation measurements on the Si(111) 7×7 surface with an optimized qPlus AFM/STM technique

• Zsolt Majzik,
• Martin Setvín,
• Andreas Bettac,
• Albrecht Feltz,
• Vladimír Cháb and
• Pavel Jelínek

Beilstein J. Nanotechnol. 2012, 3, 249–259, doi:10.3762/bjnano.3.28

• tunneling-current and the deflection signal. The efficiency of this experimental setup is demonstrated through topography and site-specific force/tunneling-spectroscopy measurements on the Si(111) 7×7 surface. The results show an excellent agreement with previously reported data measured by optical

• resolution on the prototypical Si(111) 7×7 surface [5]. Among others, this seminal work initiated a fast progression of the FM-AFM technique over the past decade [6][7]. At the beginning, mainly silicon-based cantilevers oscillating with large amplitudes (tens of nanometers) were used, because they possess

• -voltage converter used for detection of the tunneling current and the stray capacitance between the internal connections of the microscope. Based on our findings, we made some modifications of the sensor design and of the internal wiring too. Simultaneous STM/AFM measurements on the Si(111) 7×7 surface

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

• ) reconstruction of Si(111), obtaining this same level of resolution on rough surfaces presents an experimental challenge. Under suitable conditions, atomic resolution of amorphous surfaces has been achieved. For atomically resolved images of barium silicate glass, UHV contact-mode AFM with a relatively high

• improvement in resolution (Figure 1a and Figure 1b). Features with radius of curvature as small as 2.3 nm were observed in images with the supersharp tip (Figure 1a) [19]. Yet, under comparable experimental conditions, the (7 × 7) structure of Si(111) could be discerned with atomic resolution without the aid

• of a supersharp tip (Figure 1c). Atomic resolution on Si(111) depends on the short-range chemical forces and the bonding configuration of the tip apex atom [20][21][22][23], whereas long-range vdW interactions are a constant background force for AFM imaging of this and other flat surfaces. In

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

• 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

• to its large spring constant of about 9000 N/m. The force-spectroscopy measurements were performed on the organic molecule 3,4,9,10-perylene-tetracarboxylic-dianhydride (PTCDA) grown on a Ag/Si(111) √3 × √3 surface. PTCDA has been extensively studied as a candidate for organic devices [10][11][12][13

Molecular-resolution imaging of pentacene on KCl(001)

• Julia L. Neff,
• Jan Götzen,
• Enhui Li,
• Michael Marz and
• Regina Hoffmann-Vogel

Beilstein J. Nanotechnol. 2012, 3, 186–191, doi:10.3762/bjnano.3.20

• temperatures. For the data shown here the sample was cooled to below 28 K and investigated under conditions of a nonconstant thermal drift smaller than 0.1 Å/s. The piezo-scanner calibration was double checked by performing high-resolution measurements on the Si(111) surface. To reduce the influence of long

Self-assembly of octadecyltrichlorosilane: Surface structures formed using different protocols of particle lithography

• ChaMarra K. Saner,
• Kathie L. Lusker,
• Zorabel M. LeJeune,
• Wilson K. Serem and
• Jayne C. Garno

Beilstein J. Nanotechnol. 2012, 3, 114–122, doi:10.3762/bjnano.3.12

• capabilities for the high-throughput fabrication of nanopatterns from organosilane self-assembled monolayers, which offers the opportunity to study surface-based chemical reactions at the molecular level. Nanopatterns of octadecyltrichlorosilane (OTS) were prepared on surfaces of Si(111) using designed

• force microscopy (AFM) images. Images of OTS nanostructures prepared on Si(111) that were generated by the different approaches provide insight into the self-assembly mechanism of OTS, and particularly into the role of water and solvents in hydrolysis and silanation. Keywords: atomic force microscopy

• organosilane nanostructures are compared, as shown in Figure 1. Each approach uses a different strategy for applying the organosilanes to the masked surface of Si(111), using either heated-vapor deposition, contact printing, or immersion in a silane solution. For comparison of the different particle

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

• depressions corresponding to known defect-based protrusions on the surface with tips displaying similar inverted contrast over the clean surface (Supporting Information File 1). Inverted images have previously been reported during NC-AFM imaging of Si(111) [16], but in this instance this was likely due to the

Distinguishing magnetic and electrostatic interactions by a Kelvin probe force microscopy–magnetic force microscopy combination

• Miriam Jaafar,
• Oscar Iglesias-Freire,
• Luis Serrano-Ramón,
• Manuel Ricardo Ibarra,
• Jose Maria de Teresa and
• Agustina Asenjo

Beilstein J. Nanotechnol. 2011, 2, 552–560, doi:10.3762/bjnano.2.59

• all the samples studied in this paper is As-doped (n-type) Si(111). Different nano- or submicrometric structures were grown for this experiment: (i) Co straight wires 5 μm long, 500 nm wide and a thickness ranging from 10 nm to 400 nm; (ii) Co L-shaped wires with long arm of 10 μm and short arm of 5

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

• being dip-coated, the polymer was removed by oxygen plasma treatment (see Figure 6). Self-assembled monolayer coated silicon wafer The molecular surfaces were prepared by self-assembling organosilane molecules onto silicon wafers Si(111) with a native thin oxide (SiO2) layer of ~1.5 nm. The organosilane

Magnetic coupling mechanisms in particle/thin film composite systems

• Giovanni A. Badini Confalonieri,
• Philipp Szary,
• Durgamadhab Mishra,
• Maria J. Benitez,
• Mathias Feyen,
• An Hui Lu,
• Leonardo Agudo,
• Gunther Eggeler,
• Oleg Petracic and
• Hartmut Zabel

Beilstein J. Nanotechnol. 2010, 1, 101–107, doi:10.3762/bjnano.1.12

• section NPs/thin-film system showing the CoO layer at the interface with NPs. (b) The corresponding diffraction pattern where the following phases are identified: 1) CoO (200), 2) Fe2O3 (311), 3) Si (111), 4) Fe2O3 (111). ZFC/FC magnetic moment vs temperature measured in 500 Oe for a NP monolayer (green