Ferromagnetic behaviour of ZnO: the role of grain boundaries

• Boris B. Straumal,
• Svetlana G. Protasova,
• Andrei A. Mazilkin,
• Eberhard Goering,
• Gisela Schütz,
• Petr B. Straumal and
• Brigitte Baretzky

Beilstein J. Nanotechnol. 2016, 7, 1936–1947, doi:10.3762/bjnano.7.185

• (10 to 75 nm). No dependence on temperature or penetration depth was observed. Therefore, the µSR spectra were obtained by averaging the data obtained at different temperatures and different sample penetration depths in order to improve the signal to noise ratio. Three different samples were

Noise in NC-AFM measurements with significant tip–sample interaction

• Jannis Lübbe,
• Matthias Temmen,
• Philipp Rahe and
• Michael Reichling

Beilstein J. Nanotechnol. 2016, 7, 1885–1904, doi:10.3762/bjnano.7.181

• the intrinsic value Q0 [14][15]. Our analysis can, however, be applied to any NC-AFM detection scheme and sample environment, specifically also to measurements in liquids where signal-to-noise-ratio considerations play a paramount role [16][17][18]. From our findings, we derive a general strategy for

• optimum in stability, accuracy and signal-to-noise ratio can be done by a rational, systematic approach following the findings described in this paper, provided the measurement system is well characterised and offers sufficient choice and flexibility in system parameter settings. The starting point is

Monolayer graphene/SiC Schottky barrier diodes with improved barrier height uniformity as a sensing platform for the detection of heavy metals

• Ivan Shtepliuk,
• Jens Eriksson,
• Volodymyr Khranovskyy,
• Tihomir Iakimov,
• Anita Lloyd Spetz and
• Rositsa Yakimova

Beilstein J. Nanotechnol. 2016, 7, 1800–1814, doi:10.3762/bjnano.7.173

• is graphene [14]. Due to its large surface area (2600 m2/g) [15], high chemical activity [16] and exceptionally high signal-to-noise ratio [17], graphene provides a rich platform for surface chemistry and the desirable conditions for detection of heavy metals because of the strong sensitivity of its

Dynamic of cold-atom tips in anharmonic potentials

• Tobias Menold,
• Peter Federsel,
• Carola Rogulj,
• Hendrik Hölscher,
• József Fortágh and
• Andreas Günther

Beilstein J. Nanotechnol. 2016, 7, 1543–1555, doi:10.3762/bjnano.7.148

• good signal-to-noise ratio, all data have thus been averaged over 50 experimental cycles. At higher outcoupling rates, tip oscillations can be detected in a single run. Figure 8 shows an example of the measured ion signal as averaged over 50 experimental runs with the outcoupling position tuned to y0

• single particle events rather than the binned detector signal to improve the signal-to-noise ratio. Figure 9 shows an example of the binned detector signal alongside the Fourier transform and the autocorrelation function as extracted from the measurement at y0 = 32.6 μm (Δ = 2π × 2.03 MHz). The

• the correlation analysis. Signal-to-noise ratio As described earlier, the detection signal strongly depends on the outcoupling position. For an application-orientated assignment of a cold-atom tip, the signal-to-noise ratio should thus be optimized. Therefore, we take a series of oscillation

Generalized Hertz model for bimodal nanomechanical mapping

• Aleksander Labuda,
• Marta Kocuń,
• Waiman Meinhold,
• Deron Walters and
• Roger Proksch

Beilstein J. Nanotechnol. 2016, 7, 970–982, doi:10.3762/bjnano.7.89

• . In AM-AM and AM-PM, the second eigenmode drive frequency is held fixed. In that case, when the second eigenmode resonance frequency shifts by more than its bandwidth (fc/2Qc), the signal-to-noise ratio degrades because the signal drops relative to the noise floor. Furthermore, in AM-AM operation, A2

• decreases upon interaction with the surface – further aggravating the drop in signal-to-noise ratio. It is therefore often advisable to operate the second eigenmode in FM mode in practical situations. On the other hand, the first eigenmode typically undergoes more modest changes in resonance frequency upon

• interaction with the surface. Also, these changes are controllable by the AFM user by the setting of an amplitude setpoint. For this reason, AM operation on the first eigenmode does not cause the same decrease in signal-to-noise ratio often observed on the second eigenmode. More importantly, dynamic AFM

Investigating organic multilayers by spectroscopic ellipsometry: specific and non-specific interactions of polyhistidine with NTA self-assembled monolayers

• Ilaria Solano,
• Pietro Parisse,
• Ornella Cavalleri,
• Federico Gramazio,
• Loredana Casalis and
• Maurizio Canepa

Beilstein J. Nanotechnol. 2016, 7, 544–553, doi:10.3762/bjnano.7.48

• Experimental section. δΔ2,1 and δΨ2,1 difference spectra shown in Figure 4a,b are representative of the observed behavior. Despite the reduced refractive index mismatch between the film and the ambient and the use of cell windows tending to lower the signal-to-noise ratio, the emerging picture appears rather

Active multi-point microrheology of cytoskeletal networks

• Tobias Paust,
• Tobias Neckernuss,
• Lina Katinka Mertens,
• Ines Martin,
• Michael Beil,
• Paul Walther,
• Thomas Schimmel and
• Othmar Marti

Beilstein J. Nanotechnol. 2016, 7, 484–491, doi:10.3762/bjnano.7.42

• ability of the network to transmit mechanical forces. We also take a closer look at the influence of noise on lock-in measurements and state some simple rules for improving the signal-to-noise ratio. Keywords: cytoskeleton; intermediate filaments; lock-in technique; microrheology; optical tweezers

• closer look at the signal-to-noise ratio (SNR) is also necessary in order to to ensure applicability of the method over the whole range of experimentally accessible parameters. With this technique we characterized keratin networks with crosslinks of different strength. The concept of the lock-in

Length-extension resonator as a force sensor for high-resolution frequency-modulation atomic force microscopy in air

• Hannes Beyer,
• Tino Wagner and
• Andreas Stemmer

Beilstein J. Nanotechnol. 2016, 7, 432–438, doi:10.3762/bjnano.7.38

• comparable to the value measured by Giessibl et al. for signal-to-noise ratio calculations of the LER [9]. Compensation of environment-induced frequency shift The frequency shift signal Δf is a measure of the force gradient kts according to Δf = f0kts/2k, where f0 is the free resonance frequency. The high

Functional fusion of living systems with synthetic electrode interfaces

• Oskar Staufer,
• Sebastian Weber,
• C. Peter Bengtson,
• Hilmar Bading,
• Joachim P. Spatz and
• Amin Rustom

Beilstein J. Nanotechnol. 2016, 7, 296–301, doi:10.3762/bjnano.7.27

• -noise ratio is likely due to an increased electrical coupling coefficient based on the “close” contact between the sharp, monocrystalline electrode tips and the plasma membrane in combination with the PC isolation layer increasing the seal resistance. Comparable improvements of the signal-to-noise ratio

• were achieved with several nano- or microstructured electrode surfaces, such as chemically functionalized micrometer-sized mushroom-shaped gold protrusions [13][14], highlighting the general advantages of such surfaces over planar electrodes. The signal-to-noise ratio of intracellular NEI measurements

• potential changes frequently became detectable (Figure 3, green). These are well understood for Physarum p. and closely related to its oscillating cytoplasmic shuttle streaming that develops over a similar time frame [2]. When compared to PGE/PGE recordings, the significant enhancement of the signal-to

High-bandwidth multimode self-sensing in bimodal atomic force microscopy

• Michael G. Ruppert and
• S. O. Reza Moheimani

Beilstein J. Nanotechnol. 2016, 7, 284–295, doi:10.3762/bjnano.7.26

• strain sensitivity on the fifth eigenmode leading to a remarkable signal-to-noise ratio. Experimental results using bimodal AFM imaging on a two component polymer sample validate that the self-sensing scheme can therefore be used to provide both the feedback signal, for topography imaging on the

• values obtained during AFM imaging. To qualify the resolution of the overall AFM system, a noise image with the actively driven cantilever in contact with the sample surface should be acquired [35] which takes into account all contributing noise processes. Additionally, the signal-to-noise-ratio (SNR) is

Single-molecule mechanics of protein-labelled DNA handles

• Vivek S. Jadhav,
• Dorothea Brüggemann,
• Florian Wruck and
• Martin Hegner

Beilstein J. Nanotechnol. 2016, 7, 138–148, doi:10.3762/bjnano.7.16

• lengths, one can choose a certain trap separation during experiments that minimizes contributions due to crosstalk. DH lengths of 1000, 3034 and 4056 bp were chosen for the PDHs in this study. Short handles with greater stiffness could be produced quite easily and increase the signal-to-noise ratio (SNR

• increasing the distance between the two optically trapped beads. For nanomechanical experiments short molecular handles are preferred due to their increased mechanical stiffness, resulting in a favourable signal-to-noise ratio [14]. In order to achieve optimal positional and force resolution a balance had to

• the signal-to-noise ratio. The upper PDHs length limit is defined by the range of the steerable piezo-mirror (ca. 8 µm in the device used here). For tweezers systems utilizing a pipette and an optical trap (see Figure 1a–d) PDH molecules as short as 30 nm up to 30 µm can be investigated. Using these

Chemical bath deposition of textured and compact zinc oxide thin films on vinyl-terminated polystyrene brushes

• Nina J. Blumenstein,
• Caroline G. Hofmeister,
• Peter Lindemann,
• Cheng Huang,
• Johannes Baier,
• Andreas Leineweber,
• Stefan Walheim,
• Christof Wöll,
• Thomas Schimmel and
• Joachim Bill

Beilstein J. Nanotechnol. 2016, 7, 102–110, doi:10.3762/bjnano.7.12

• signal-to-noise ratio, PS brushes grafted to a Si-wafer coated with 10 nm SiO2, 100 nm Au and 5 nm Ti as adhesive layer between Au and Si were prepared [46]. For the sample measurement between 900 and 1300 scans have been cumulated, the spectra were recorded until no water bands could be observed in the

Probing the local environment of a single OPE3 molecule using inelastic tunneling electron spectroscopy

• Riccardo Frisenda,
• Mickael L. Perrin and
• Herre S. J. van der Zant

Beilstein J. Nanotechnol. 2015, 6, 2477–2484, doi:10.3762/bjnano.6.257

• extract a reliable IETS signal. In our approach, we record a large number of IVs, from which we calculate the first and the second derivative. We then divide point by point the second derivative by the first derivative to obtain the IETS signal. To increase the signal-to-noise ratio and reduce the effect

Blue and white light emission from zinc oxide nanoforests

• Nafisa Noor,
• Luca Lucera,
• Thomas Capuano,
• Venkata Manthina,
• Alexander G. Agrios,
• Helena Silva and
• Ali Gokirmak

Beilstein J. Nanotechnol. 2015, 6, 2463–2469, doi:10.3762/bjnano.6.255

• PIN diode to the sample was adjusted to achieve adequate signal-to-noise ratio without saturating the diode during the experiments. The voltage output of the built-in amplifier was significantly larger than any noise or perturbations coupled into the signal lines caused by the fast pulses. Hence, this

Au nanoparticle-based sensor for apomorphine detection in plasma

• Chiara Zanchi,
• Andrea Lucotti,
• Matteo Tommasini,
• Sebastiano Trusso,
• Ugo de Grazia,
• Emilio Ciusani and
• Paolo M. Ossi

Beilstein J. Nanotechnol. 2015, 6, 2224–2232, doi:10.3762/bjnano.6.228

• experiences in the biological matrix as compared to the aqueous solution. To reach a comparable SERS intensity with respect to 100 µg/mL APO in water, an acquisition time of 10 s was applied, while 60 s was the acquisition time required for a reasonable signal-to-noise ratio of the SERS spectrum of 20 µg/mL

• by the selection of two SERS peaks. Minimal sample preparation and the capability to operate in an aqueous environment make the detection of APO by means of this technique rapid, with good signal-to-noise ratio, and characterized by adequate spatial reproducibility. The method is promising for

• dynamic range of the sensor To be considered a useful SERS-based method for drug detection, the procedure, based on the use of gold substrates pulsed laser deposition, should be rapid and quantitative. An acquisition time of 5 s, which corresponds to a fast measurement with an adequate signal-to-noise

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

• transitions and observations, respectively. As the noise at the output, , increases for a fixed , the bandwidth is reduced (Figure 7a). The ratio resembles a signal-to-noise ratio (SNR), which increases for large K and small filter bandwidths BW. The closed-loop bandwidth is a function of this SNR. Therefore

Electrochemical coating of dental implants with anodic porous titania for enhanced osteointegration

• Amirreza Shayganpour,
• Alberto Rebaudi,
• Pierpaolo Cortella,
• Alberto Diaspro and
• Marco Salerno

Beilstein J. Nanotechnol. 2015, 6, 2183–2192, doi:10.3762/bjnano.6.224

• measurements, given the limited thickness of APT, we had to use collecting conditions of low magnification (objective of 10×), high laser power (≈100 mW) and long accumulation time (1 min) to obtain spectra with reasonable signal to noise ratio. A representative Raman spectrum is presented in Figure 5

Imaging of carbon nanomembranes with helium ion microscopy

• André Beyer,
• Henning Vieker,
• Robin Klett,
• Hanno Meyer zu Theenhausen,
• Polina Angelova and
• Armin Gölzhäuser

Beilstein J. Nanotechnol. 2015, 6, 1712–1720, doi:10.3762/bjnano.6.175

• particle microscopy techniques such as scanning electron microscopy (SEM) or helium ion microscopy (HIM). As illustrated in Supporting Information File 1, Figure S1, SEM shows a low signal-to-noise-ratio for freestanding CNMs, especially at higher magnifications, due to charging issues [4][16]. This tends

• to be destructive for freestanding membranes. For example, an attempt at imaging perforated CNMs with SEM failed due to charging-induced rupture during the imaging process [9]. On the other hand, HIM is very well-suited to image CNMs with high signal-to-noise-ratio at high magnification. In this

• , the high surface sensitivity of the HIM is well suited to obtain CNM images with high signal-to-noise-ratio. It is also important to note that the helium beam easily penetrates the CNM and also strikes objects below the freestanding membrane, for example, the sample holder. Figure 1 shows an example

Possibilities and limitations of advanced transmission electron microscopy for carbon-based nanomaterials

• Xiaoxing Ke,
• Carla Bittencourt and
• Gustaaf Van Tendeloo

Beilstein J. Nanotechnol. 2015, 6, 1541–1557, doi:10.3762/bjnano.6.158

• . Fortunately this has changed over the last decade. The introduction of spherical-aberration-corrected lenses [6] has paved the way out of this dilemma by improving the spatial resolution and increasing the signal to noise ratio at the same time. This has a dramatic impact when imaging at low accelerating

• generally accepted as reasonable. Additionally, the increase of the scattering cross section at low voltage improves the signal to noise ratio for light elements as carbon and results in an enhancement in contrast [38][49]. Following the discussion on lowering the voltage, the dose of incident electrons

• thus provide a HRTEM image with an acceptable signal to noise ratio with only limited damage to the sample. The introduction of a high-speed detector may also have an impact on increasing the time resolution. In a molecular dynamics simulations on the reconstruction of vacancies, the time scale is

Atomic force microscopy as analytical tool to study physico-mechanical properties of intestinal cells

• Christa Schimpel,
• Oliver Werzer,
• Eleonore Fröhlich,
• Gerd Leitinger,
• Markus Absenger-Novak,
• Birgit Teubl,
• Andreas Zimmer and
• Eva Roblegg

Beilstein J. Nanotechnol. 2015, 6, 1457–1466, doi:10.3762/bjnano.6.151

• . Although ESEM presents some additional beneficial features, considerable disadvantages including a high signal-to-noise ratio and/or limited resolution may arise [35]. In contrast, AFM allows high resolution (topographical) imaging of cells under (semi)hydrated, unfixed physiological conditions. Hence

Influence of the shape and surface oxidation in the magnetization reversal of thin iron nanowires grown by focused electron beam induced deposition

• Luis A. Rodríguez,
• Lorenz Deen,
• Rosa Córdoba,
• César Magén,
• Etienne Snoeck,
• Bert Koopmans and
• José M. De Teresa

Beilstein J. Nanotechnol. 2015, 6, 1319–1331, doi:10.3762/bjnano.6.136

• , we show in Figure 2a and Figure 2b the results for two nanowires from the second batch with tNom of 10 and 35 nm. The signal-to-noise ratio is ten, certainly enough to determine the coercive field, which is given by the measured MOKE field at the mid-point between the two saturation values at high

Scanning reflection ion microscopy in a helium ion microscope

• Yuri V. Petrov and
• Oleg F. Vyvenko

Beilstein J. Nanotechnol. 2015, 6, 1125–1137, doi:10.3762/bjnano.6.114

• the RIM measurements are obviously defined by the signal-to-noise ratio that increases with the image acquisition duration. There are two factors that limit measurement time in RIM: the ion beam induced deposition (IBID) of hydrocarbons and the sputtering of the surface material. The first problem

Entropy effects in the collective dynamic behavior of alkyl monolayers tethered to Si(111)

• Christian Godet

Beilstein J. Nanotechnol. 2015, 6, 583–594, doi:10.3762/bjnano.6.60

• of the OML. In contrast with alternative dynamic probes, such as nuclear magnetic resonance, which are limited by a poor signal-to-noise ratio and require functionalization of 3D nanoparticles or porous solids [3], admittance spectroscopy is sensitive to 0.3 picomoles of carboxylic acid dipoles [40

A scanning probe microscope for magnetoresistive cantilevers utilizing a nested scanner design for large-area scans

• Tobias Meier,
• Alexander Förste,
• Ali Tavassolizadeh,
• Karsten Rott,
• Dirk Meyners,
• Roland Gröger,
• Günter Reiss,
• Eckhard Quandt,
• Thomas Schimmel and
• Hendrik Hölscher

Beilstein J. Nanotechnol. 2015, 6, 451–461, doi:10.3762/bjnano.6.46

• a squared geometry used in this work shows the highest strain sensitivity of 2 × 10−7 Å, at a bias field angle α of 115° towards the magnetization of the reference layer. For this measurement, we can extract a signal-to-noise ratio of 900 at a bandwidth of 100 kHz which allows one to measure the

Overview about the localization of nanoparticles in tissue and cellular context by different imaging techniques

• Anja Ostrowski,
• Daniel Nordmeyer,
• Alexander Boreham,
• Cornelia Holzhausen,
• Lars Mundhenk,
• Christina Graf,
• Martina C. Meinke,
• Annika Vogt,
• Sabrina Hadam,
• Jürgen Lademann,
• Eckart Rühl,
• Ulrike Alexiev and
• Achim D. Gruber

Beilstein J. Nanotechnol. 2015, 6, 263–280, doi:10.3762/bjnano.6.25

• and subcellular constituents in detail [110]. Spectral imaging and unmixing offers substantial improvement in signal-to-noise ratio and image contrast compared to the use of monochrome band-pass emission filters as employed in conventional fluorescence microscopes [111]. This approach also facilitates