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

• , respectively. To control the instrument, a commercially available electronic equipment is used (SPECS, Nanonis). For bimodal measurement techniques, such as KPFM and SCFM, two independent phase lock loop (PLL, Nanonis OC4) circuits are necessary. The SPM software consists of several modules allowing to control

A simple and efficient quasi 3-dimensional viscoelastic model and software for simulation of tapping-mode atomic force microscopy

• Santiago D. Solares

Beilstein J. Nanotechnol. 2015, 6, 2233–2241, doi:10.3762/bjnano.6.229

• of force curve for bimodal AFM, showing a double impact. The blue arrows indicate in each case the position where the tip first reaches the sample, and the red arrows indicate the position where the tip leaves the sample. Van der Waals forces have been included in the attractive (noncontact) region

• interacting with a cavity on the surface with respect to a tip interacting with a flat surface; (d) typical Q3D force curves for bimodal AFM imaging using the first and third eigenmodes. Note that the level of indentation increases as A3 increases. Note also the resemblance to the force curve shown in Figure

• constant k = 4 N/m, eigenmode quality factors Q1 = 150, Q2 = 450, Q3 = 750; tip radius of curvature R = 20 nm, and SLS parameters (see Figure 1) k1 = k2 = 7.5 × 10−2 N/m/nm2, and c = 1.0 × 10−7 N s/m/nm2 (monomodal AFM) and 2.5 × 10−8 N s/m/nm2 (bimodal AFM). (a) Force curve for a 20 nm radius tip with a

Selective porous gates made from colloidal silica nanoparticles

• Roberto Nisticò,
• Paola Avetta,
• Paola Calza,
• Debora Fabbri,
• Giuliana Magnacca and
• Dominique Scalarone

Beilstein J. Nanotechnol. 2015, 6, 2105–2112, doi:10.3762/bjnano.6.215

• distribution curve (Figure 3B) indicates a complex pore size distribution. In detail, pores present a bimodal distribution, with the presence of meso/macroporosity in the range 15–200 nm, probably due to interparticle voids (i.e., depth-filter porosity), together with a certain degree of microporosity in the

Heterometal nanoparticles from Ru-based molecular clusters covalently anchored onto functionalized carbon nanotubes and nanofibers

• Deborah Vidick,
• Xiaoxing Ke,
• Michel Devillers,
• Claude Poleunis,
• Arnaud Delcorte,
• Pietro Moggi,
• Gustaaf Van Tendeloo and
• Sophie Hermans

Beilstein J. Nanotechnol. 2015, 6, 1287–1297, doi:10.3762/bjnano.6.133

• the nanocarbon surface. The ligands of the anchored molecular species are then removed by gentle thermal treatment in order to form nanoparticles. In the case of Au-containing clusters, removal of gold atoms from the clusters and agglomeration leads to a bimodal distribution of nanoparticles at the

• -containing clusters, a bimodal size distribution of metal nanoparticles was obtained due to gold segregation from the cluster cores and strong aggregation. In the case of Ru–Pt precursors, heterometal nanoparticles of ultrasmall size were formed on the carbon fibers and MWNTs. We used a combination of HRTEM

High sensitivity and high resolution element 3D analysis by a combined SIMS–SPM instrument

• Yves Fleming and
• Tom Wirtz

Beilstein J. Nanotechnol. 2015, 6, 1091–1099, doi:10.3762/bjnano.6.110

• rate; Introduction With the progress of miniaturisation, driven by future needs in various fields in materials and life sciences, the 3D analysis of devices and material structures becomes increasingly challenging. As a consequence, the interest for performing bimodal or even multimodal nano-analysis

Optimization of phase contrast in bimodal amplitude modulation AFM

• Mehrnoosh Damircheli,
• Amir F. Payam and
• Ricardo Garcia

Beilstein J. Nanotechnol. 2015, 6, 1072–1081, doi:10.3762/bjnano.6.108

• Bimodal force microscopy has expanded the capabilities of atomic force microscopy (AFM) by providing high spatial resolution images, compositional contrast and quantitative mapping of material properties without compromising the data acquisition speed. In the first bimodal AFM configuration, an amplitude

• feedback loop keeps constant the amplitude of the first mode while the observables of the second mode have not feedback restrictions (bimodal AM). Here we study the conditions to enhance the compositional contrast in bimodal AM while imaging heterogeneous materials. The contrast has a maximum by decreasing

• the amplitude of the second mode. We demonstrate that the roles of the excited modes are asymmetric. The operational range of bimodal AM is maximized when the second mode is free to follow changes in the force. We also study the contrast in trimodal AFM by analyzing the kinetic energy ratios. The

From lithium to sodium: cell chemistry of room temperature sodium–air and sodium–sulfur batteries

• Philipp Adelhelm,
• Pascal Hartmann,
• Conrad L. Bender,
• Martin Busche,
• Christine Eufinger and
• Juergen Janek

Beilstein J. Nanotechnol. 2015, 6, 1016–1055, doi:10.3762/bjnano.6.105

Silica micro/nanospheres for theranostics: from bimodal MRI and fluorescent imaging probes to cancer therapy

• Shanka Walia and
• Amitabha Acharya

Beilstein J. Nanotechnol. 2015, 6, 546–558, doi:10.3762/bjnano.6.57

• sites in vivo. In this sense, bimodal imaging probes that simultaneously enable magnetic resonance imaging and fluorescence imaging have gained tremendous attention because disease sites can be characterized quick and precisely through synergistic multimodal imaging. But such hybrid nanocomposite

• will cover a full description of MRI-active and fluorescent multifunctional silica micro/nanospheres including the design of the probe, different characterization methods and their application in imaging and treatment in cancer. Keywords: bimodal imaging; fluorescence imaging; magnetic nanoparticles

• NPs can be maximized. In our earlier review, we have compiled the literature reports on the biological studies of the hybrid nanocomposite materials, exclusively composed of luminescent quantum dots (QDs) and magnetically active iron oxide as bimodal imaging agents [2]. In this sense, nanostructured

Dynamic force microscopy simulator (dForce): A tool for planning and understanding tapping and bimodal AFM experiments

• Horacio V. Guzman,
• Pablo D. Garcia and
• Ricardo Garcia

Beilstein J. Nanotechnol. 2015, 6, 369–379, doi:10.3762/bjnano.6.36

• experiments. The simulator presents the cantilever–tip dynamics for two dynamic AFM methods, tapping mode AFM and bimodal AFM. It can be applied for a wide variety of experimental situations in air or liquid. The code provides all the variables and parameters relevant in those modes, for example, the

• simulations. Finally, the accuracy of dForce has been tested against numerical simulations performed during the last 18 years. Keywords: bimodal AFM; dynamic AFM; nanomechanics; numerical simulations; tapping mode AFM; Introduction Numerical simulations have played a pivotal role to advance the

• spatial resolution and contrast of different dynamic AFM methods has also been studied by simulations [28][30][31]. Finally, the emergence of multifrequency AFM [32] in particular bimodal [33][34], trimodal [35], intermodulation [36] or torsional harmonics [37] has been supported by simulations [38]. In

High-frequency multimodal atomic force microscopy

• Adrian P. Nievergelt,
• Jonathan D. Adams,
• Pascal D. Odermatt and
• Georg E. Fantner

Beilstein J. Nanotechnol. 2014, 5, 2459–2467, doi:10.3762/bjnano.5.255

• far remained the domain of a handful of highly-specialized instruments. In this report, we present high-resonance-frequency bimodal AFM imaging by using an AFM readout head designed for high-frequency drive and readout of small cantilevers. Our head is compatible with the Bruker MultiMode AFM, a

• our system for noise performance will decrease the baseline noise value further [35]. Dissipation imaging Bimodal imaging The capability for clean, high-frequency cantilever excitation, and low-noise, high-frequency deflection readout provide a powerful platform for extending multifrequency techniques

• to higher frequencies. For simultaneous high-frequency imaging and mechanical property mapping, we use a bimodal resonant technique which tracks topography in amplitude modulation on the first eigenmode [5][38]. This mode is one of the possibilities of achieving materials contrast while

Inorganic Janus particles for biomedical applications

• Isabel Schick,
• Steffen Lorenz,
• Dominik Gehrig,
• Stefan Tenzer,
• Wiebke Storck,
• Karl Fischer,
• Dennis Strand,
• Frédéric Laquai and
• Wolfgang Tremel

Beilstein J. Nanotechnol. 2014, 5, 2346–2362, doi:10.3762/bjnano.5.244

• particles used for catalysis [52][63][64], drug delivery [65], bimodal bioimaging [36][66][67][68], and biomedical applications [69][70] such as cancer treatment [71] are dumbbell-like Au@Fe3O4 nanoparticles. As no ternary Au-Fe-O phase or a gold oxide is present under the experimental conditions, there is

Advanced atomic force microscopy techniques II

• Thilo Glatzel,
• Ricardo Garcia and
• Thomas Schimmel

Beilstein J. Nanotechnol. 2014, 5, 2326–2327, doi:10.3762/bjnano.5.241

• with real parameters [22]. Furthermore, technical contributions discuss the impact of thermal frequency drift of quartz-based force sensors at low temperatures to the accuracy of the force measurements [23] and the trade-offs in sensitivity and sampling depth in bimodal and trimodal AFM [24]. The

Nanobioarchitectures based on chlorophyll photopigment, artificial lipid bilayers and carbon nanotubes

• Marcela Elisabeta Barbinta-Patrascu,
• Stefan Marian Iordache,
• Ana Maria Iordache,
• Nicoleta Badea and
• Camelia Ungureanu

Beilstein J. Nanotechnol. 2014, 5, 2316–2325, doi:10.3762/bjnano.5.240

• vesicles was confirmed by DLS. The size distribution profile (Figure 2) was bimodal for both types of liposomes. From these results, one can see that the cholesterol-containing artificial lipid bilayers have smaller dimensions (Zaverage = 567.6 ± 116.2; PDI = 0.322 ± 0.067) than liposomes without

Dynamic calibration of higher eigenmode parameters of a cantilever in atomic force microscopy by using tip–surface interactions

• Stanislav S. Borysov,
• Daniel Forchheimer and
• David B. Haviland

Beilstein J. Nanotechnol. 2014, 5, 1899–1904, doi:10.3762/bjnano.5.200

• different narrow bands near resonances contain the same information about the unknown force parameters [28]. Calculation details In the rest of the paper, we consider a bimodal case implying straightforward generalization for N > 2 eigenmodes. Equation 1 is integrated by using CVODE [34] for two different

• bimodal stiff cantilever with the eigenmode amplitudes A1 = A2 = 12.5 nm and reference height h = 17 nm. Cross-sections for different values of z and are shown: The projections (1) and (2) correspond to the lines = 0.05 m/s and z = 0 nm respectively; the conservative part (3) corresponds to the line

Probing viscoelastic surfaces with bimodal tapping-mode atomic force microscopy: Underlying physics and observables for a standard linear solid model

• Santiago D. Solares

Beilstein J. Nanotechnol. 2014, 5, 1649–1663, doi:10.3762/bjnano.5.176

• single-mode and bimodal atomic force microscopy (AFM) with particular focus on the viscoelastic interactions occurring during tip–sample impact. The surface is modeled by using a standard linear solid model, which is the simplest system that can reproduce creep compliance and stress relaxation, which are

• fundamental behaviors exhibited by viscoelastic surfaces. The relaxation of the surface in combination with the complexities of bimodal tip–sample impacts gives rise to unique dynamic behaviors that have important consequences with regards to the acquisition of quantitative relationships between the sample

• properties and the AFM observables. The physics of the tip–sample interactions and its effect on the observables are illustrated and discussed, and a brief research outlook on viscoelasticity measurement with intermittent-contact AFM is provided. Keywords: amplitude-modulation; bimodal; dissipation

Multi-frequency tapping-mode atomic force microscopy beyond three eigenmodes in ambient air

• Santiago D. Solares,
• Sangmin An and
• Christian J. Long

Beilstein J. Nanotechnol. 2014, 5, 1637–1648, doi:10.3762/bjnano.5.175

• future research opportunities. Keywords: amplitude-modulation; bimodal; frequency-modulation; multi-frequency atomic force microscopy; multimodal; open loop; trimodal; Introduction Multi-frequency atomic force microscopy (AFM) refers to a family of techniques in which the microcantilever probe is

• -eigenmode methods [19][20][21][22], which are of particular interest since their purpose is to carry out multiple characterization functions at the same time. Specifically, bimodal AFM methods were developed to perform simultaneous topographical imaging and compositional mapping [2][3], and trimodal methods

• were later introduced to add imaging depth modulation capability to the bimodal schemes [9]. Although there is not yet an obvious need for methods involving more than three eigenmodes, and although a number of challenges are expected in terms of cantilever quality and drive systems performance (see

Current state of laser synthesis of metal and alloy nanoparticles as ligand-free reference materials for nano-toxicological assays

• Christoph Rehbock,
• Jurij Jakobi,
• Lisa Gamrad,
• Selina van der Meer,
• Daniela Tiedemann,
• Ulrike Taylor,
• Wilfried Kues,
• Detlef Rath and
• Stephan Barcikowski

Beilstein J. Nanotechnol. 2014, 5, 1523–1541, doi:10.3762/bjnano.5.165

• fluence, alternative photomechanical ablation mechanisms like explosive boiling were reported, which result in bimodal particle size distributions (Figure 1B) [50]. Even though a relatively broad size distribution of nanoparticles fabricated by PLAL may be beneficial to simulate toxicological effects

• a veritable method to vary particle sizes in gold nanoparticles, though this method primarily gives access to small particles and in some cases the parallel presence of educt and product during the process may lead to bimodal size distributions. As PLFL primarily yields smaller nanoparticles, a

• obtained from PLAL in deionized water using picosecond (black curve) and nanosecond (red curve) pulses. B) Gold nanoparticles obtained from femtosecond laser ablation showing a bimodal particle size distribution. (Reprinted with permission from [50]. Copyright 2003 AIP Publishing ICC). Size control of

Formation of Cu_xAu_1−x phases by cold homogenization of Au/Cu nanocrystalline thin films

• Alona Tynkova,
• Gabor L. Katona,
• Gabor A. Langer,
• Sergey I. Sidorenko,
• Svetlana M. Voloshko and
• Dezso L. Beke

Beilstein J. Nanotechnol. 2014, 5, 1491–1500, doi:10.3762/bjnano.5.162

• (bimodal GB network) [25]. It was shown in [25] that in the latter case the GB diffusion starts along GBs with the largest diffusivities and there is only short penetration along GBs with small diffusivity values. At longer annealing times the GB penetration length is larger than the thickness of the film

• composition in the Au layer (Figure 1c) can also be a consequence of the bimodal GB structure. A complete homogenization of the system takes place both at low temperatures for longer annealing times (Figure 1e) and/or at higher temperatures (Figure 1f). We would like to emphasize that we did not observe a

Microstructural and plasmonic modifications in Ag–TiO₂ and Au–TiO₂ nanocomposites through ion beam irradiation

• Venkata Sai Kiran Chakravadhanula,
• Yogendra Kumar Mishra,
• Venkata Girish Kotnur,
• Devesh Kumar Avasthi,
• Thomas Strunskus,
• Vladimir Zaporotchenko,
• Dietmar Fink,
• Lorenz Kienle and
• Franz Faupel

Beilstein J. Nanotechnol. 2014, 5, 1419–1431, doi:10.3762/bjnano.5.154

• confirmed the bimodal distribution of Ag nanoparticles with the presence of larger nanoparticles on top of the surface and smaller nanoparticles embedded inside the matrix. To investigate the effect of ion irradiation on metal–TiO2 nanocomposites, the deposited Au–TiO2 and Ag–TiO2 nanocomposite films (both

• films (Au–TiO2 and Ag–TiO2) in the present case exhibit bimodal particle size distributions [14] and that the TiO2 matrix is amorphous (evident from SAED patterns). For bimodal particle size distribution, the detailed TEM analysis has demonstrated that big nanoparticles are on top of the surface, while

• the smaller ones are embedded inside the nanocomposite film [39][40]. In principle, one should observe a double SPR peak corresponding to the bimodal size distribution of the nanoparticles. But in the case studied here, since the number of larger nanoparticles is very low as compared to that of

Trade-offs in sensitivity and sampling depth in bimodal atomic force microscopy and comparison to the trimodal case

• Babak Eslami,
• Daniel Ebeling and
• Santiago D. Solares

Beilstein J. Nanotechnol. 2014, 5, 1144–1151, doi:10.3762/bjnano.5.125

• experiments on Nafion® proton exchange membranes and numerical simulations illustrating the trade-offs between the optimization of compositional contrast and the modulation of tip indentation depth in bimodal atomic force microscopy (AFM). We focus on the original bimodal AFM method, which uses amplitude

• demonstrate that the two eigenmodes can be highly coupled in practice, especially when highly repulsive imaging conditions are used. Finally, we also offer a comparison with a previously reported trimodal AFM method, where the above competing effects are minimized. Keywords: amplitude modulation; bimodal

• imaging modes is now available, each with its own capabilities and applications. Among them, a family of techniques known as multifrequency AFM [2][3][4][5][6][7][8][9][10][11] has expanded considerably since the introduction of the first bimodal method by Rodriguez and Garcia in 2004 [12]. In

Plasma-assisted synthesis and high-resolution characterization of anisotropic elemental and bimetallic core–shell magnetic nanoparticles

• M. Hennes,
• A. Lotnyk and
• S. G. Mayr

Beilstein J. Nanotechnol. 2014, 5, 466–475, doi:10.3762/bjnano.5.54

• bimodal distribution. It is also noteworthy that elemental Ni particles possess a rougher surface while all particles with d ≥ 30 nm exhibit a more regular and rather smooth contour in the SEM micrographs. In order to assess the relative concentration of the components, SEM-EDX spectra (not shown herein

• -NP deposited on a TEM grid coated with lacey carbon. The same bimodal size distribution as observed in SEM is retrieved. Single CS-NPs exhibit a polycrystalline core as confirmed by FFT analysis (inset upper right) surrounded by an oxidized layer of several nanometers thickness. All particles

Challenges and complexities of multifrequency atomic force microscopy in liquid environments

• Santiago D. Solares

Beilstein J. Nanotechnol. 2014, 5, 298–307, doi:10.3762/bjnano.5.33

• discussion are mostly applicable to the cases where higher eigenmodes are driven in open loop and frequency modulation within bimodal schemes, but some concepts are also applicable to other types of multifrequency operations and to single-eigenmode amplitude and frequency modulation methods. Keywords

• : amplitude-modulation; bimodal; frequency-modulation; liquids; multifrequency atomic force microscopy; Introduction Multifrequency atomic force microscopy (AFM) refers to a family of techniques that involve simultaneous excitation of the microcantilever probe at more than one frequency [1]. The first of

• imaging conditions and to properly interpret the results, and no single recipe works in all cases. This paper explores through simulation the implications of the low-Q cantilever dynamics within the specific context of bimodal AFM imaging. The primary focus is on (i) the amplitude and phase “relaxation

Unlocking higher harmonics in atomic force microscopy with gentle interactions

• Sergio Santos,
• Victor Barcons,
• Josep Font and
• Albert Verdaguer

Beilstein J. Nanotechnol. 2014, 5, 268–277, doi:10.3762/bjnano.5.29

• ° to 0°, is observed for n = 2 only. While these jumps of nearly 180° might be of interest they are ignored from now on. The reader can refer to recent works that discuss multiple regimes of operation in bimodal AFM [31][33]. It follows that variations in Hamaker are not detected by higher harmonic

• metals such as gold, silver or copper [40]. Higher harmonic phase shifts also provide the means to decouple the true topography from an apparent topography, which is induced by compositional variations. Furthermore this outcome should still be valid in standard bimodal imaging. Overall, the proposed

AFM as an analysis tool for high-capacity sulfur cathodes for Li–S batteries

• Renate Hiesgen,
• Seniz Sörgel,
• Rémi Costa,
• Linus Carlé,
• Ines Galm,
• Natalia Cañas,
• Brigitta Pascucci and
• K. Andreas Friedrich

Beilstein J. Nanotechnol. 2013, 4, 611–624, doi:10.3762/bjnano.4.68

• use of highly ordered mesoporous carbon with a bimodal pore structure with a high specific area and a large pore volume is beneficial. It traps a part of the polysulfides for a certain time before release, thereby reduces the electrochemical irreversibility and can lead to a very high and stable

Deformation-induced grain growth and twinning in nanocrystalline palladium thin films

• Aaron Kobler,
• Jochen Lohmiller,
• Jonathan Schäfer,
• Michael Kerber,
• Anna Castrup,
• Ankush Kashiwar,
• Patric A. Gruber,
• Karsten Albe,
• Horst Hahn and
• Christian Kübel

Beilstein J. Nanotechnol. 2013, 4, 554–566, doi:10.3762/bjnano.4.64

• crystallite boundary maps corresponding to 0%, 5% and 10% strain are displayed in Figure 4. The grain size increases, with no noticeable evolution of a bimodal size distribution and no significant preferential growth direction is observed in plane-view. In Figure 5a, a quantitative analysis of the crystallite