The memory effect of nanoscale memristors investigated by conducting scanning probe microscopy methods

• César Moreno,
• Carmen Munuera,
• Xavier Obradors and
• Carmen Ocal

Beilstein J. Nanotechnol. 2012, 3, 722–730, doi:10.3762/bjnano.3.82

• resistive state of a given modification is altered if the total range exceeds the absolute value of the corresponding Vwr. Therefore, in order to explore the true I–V curve by improving the signal-to-noise ratio and using an adequate voltage range for each HR state, we also measured individual I–V curves

Zeolites as nanoporous, gas-sensitive materials for in situ monitoring of DeNO_x-SCR

• Thomas Simons and
• Ulrich Simon

Beilstein J. Nanotechnol. 2012, 3, 667–673, doi:10.3762/bjnano.3.76

• temperature of 85 °C, observations at lower temperatures were not feasible due to the poor data quality (low signal-to-noise ratio, since the current-resolution limit of the impedance analyser is approached) at very low temperatures. Hence, the Fe-loaded catalyst shows a NH3 loss by SCR reaction at

Imaging ultra thin layers with helium ion microscopy: Utilizing the channeling contrast mechanism

• Gregor Hlawacek,
• Vasilisa Veligura,
• Stefan Lorbek,
• Tijs F. Mocking,
• Antony George,
• Raoul van Gastel,
• Harold J. W. Zandvliet and
• Bene Poelsema

Beilstein J. Nanotechnol. 2012, 3, 507–512, doi:10.3762/bjnano.3.58

• , the BSHe data presented here was recorded with lower PEs between 10 keV and 20 keV. This results in a better signal-to-noise ratio for the BSHe images. Patterns of self-assembled monolayers (SAM) were created by using a PDMS stamp and gas-phase silanization. Orthogonal stripes with an identical width

Channeling in helium ion microscopy: Mapping of crystal orientation

• Vasilisa Veligura,
• Gregor Hlawacek,
• Raoul van Gastel,
• Harold J. W. Zandvliet and
• Bene Poelsema

Beilstein J. Nanotechnol. 2012, 3, 501–506, doi:10.3762/bjnano.3.57

• PE of 15 keV. This increases the scattering probability and results in a better signal-to-noise ratio for ion-channeling contrast images. Commercially available polycrystalline gold{111} films on glass, with a chromium interlayer, were flame annealed in a hydrogen flame before the samples were loaded

• channeling contrast image recorded with the MCP detector is presented in Figure 2. Although, there is excellent contrast at the selected acceleration voltage of 20 keV and the mild dose of 1.11 × 1015 cm−2, the signal-to-noise ratio is considerably worse compared to the SE images presented above. The reason

• . First, the required ion dose for a high-quality image with a good signal-to-noise ratio is significantly lower. This is particularly important for light materials. The gold sample that has been used here has a comparatively large backscattering probability for helium atoms. The situation changes

Repulsive bimodal atomic force microscopy on polymers

• Alexander M. Gigler,
• Christian Dietz,
• Maximilian Baumann,
• Nicolás F. Martinez,
• Ricardo García and
• Robert W. Stark

Beilstein J. Nanotechnol. 2012, 3, 456–463, doi:10.3762/bjnano.3.52

• that the image contrast is related to the signal-to-noise ratio and thus difficult to quantify for heterogeneous samples. The conclusions drawn here are on the basis of the optical impression of the authors. Comparing these observations with the bimodal-spectroscopy measurements on polystyrene from the

•  6a makes clear that the cantilever response under bimodal operation was sinusoidal in both the first (f1 = 113.5 kHz) and second eigenmodes (f2 = 705.6 kHz). Furthermore, a Fourier analysis of the time traces (Figure 6b) helps to assess the signal-to-noise ratio of the signals. For the first

X-ray absorption spectroscopy by full-field X-ray microscopy of a thin graphite flake: Imaging and electronic structure via the carbon K-edge

• Carla Bittencourt,
• Adam P. Hitchock,
• Xiaoxing Ke,
• Gustaaf Van Tendeloo,
• Chris P. Ewels and
• Peter Guttmann

Beilstein J. Nanotechnol. 2012, 3, 345–350, doi:10.3762/bjnano.3.39

• , but with sufficient stability and signal integration it should be possible to measure the carbon K-edge NEXAFS of a single layer of graphene. The thickness of the studied sample ensures a good signal-to-noise ratio allowing detailed analysis of the peak form and composition. Figure 2a shows an average

Pulse-response measurement of frequency-resolved water dynamics on a hydrophilic surface using a Q-damped atomic force microscopy cantilever

• Masami Kageshima

Beilstein J. Nanotechnol. 2012, 3, 260–266, doi:10.3762/bjnano.3.29

• disadvantageous with respect to the signal-to-noise ratio. In the previous report of the step-response measurement the inferior signal-to-noise ratio of the signal hindered detailed analysis. In the present report a pulse-response measurement in which differentiation of the response signal can be dispensed with

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

• the important oscillation stability [8][9][10]. The key factor to achieve atomic resolution is the proper choice of several parameters, for example, the spring constant and the oscillation amplitude (see Table I in [11]). Theoretically, the optimal signal-to-noise ratio (SNR) is achieved at a value of

Analysis of force-deconvolution methods in frequency-modulation atomic force microscopy

• Joachim Welker,
• Esther Illek and
• Franz J. Giessibl

Beilstein J. Nanotechnol. 2012, 3, 238–248, doi:10.3762/bjnano.3.27

• ≈ 0.59 κ−1. The deconvolution quality rises again for larger amplitudes A > 7 κ−1. However, usually amplitudes in the order of the characteristic decay length of the force are desired to obtain the best signal-to-noise ratio [24]. Therefore, in a real experiment it is difficult to judge whether the Sader

Variations in the structure and reactivity of thioester functionalized self-assembled monolayers and their use for controlled surface modification

• Inbal Aped,
• Yacov Mazuz and
• Chaim N. Sukenik

Beilstein J. Nanotechnol. 2012, 3, 213–220, doi:10.3762/bjnano.3.24

• , merged signal (Figure 4B and Figure 4C). Deconvolution reveals the thiophene sulfurs at 164.5 ± 0.2 eV and 165.6 ± 0.2 eV. The overlap among the four peaks in the spectra, together with their inherently problematic signal-to-noise ratio, leads to a situation in which the expected 2:1 peak intensity ratio

qPlus magnetic force microscopy in frequency-modulation mode with millihertz resolution

• Maximilian Schneiderbauer,
• Daniel Wastl and
• Franz J. Giessibl

Beilstein J. Nanotechnol. 2012, 3, 174–178, doi:10.3762/bjnano.3.18

• frequency noise is inversely proportional to the oscillation amplitude A of the force sensor. Thus, we can reduce frequency noise by using large amplitudes and therefore minimize the . Moreover, one achieves the best signal-to-noise ratio by using an amplitude that is on the order of the decay length of the

Lifetime analysis of individual-atom contacts and crossover to geometric-shell structures in unstrained silver nanowires

• Christian Obermair,
• Holger Kuhn and
• Thomas Schimmel

Beilstein J. Nanotechnol. 2011, 2, 740–745, doi:10.3762/bjnano.2.81

• , comparable results were obtained, though with a somewhat reduced signal-to-noise ratio. Conductance histogram of electrochemically deposited atomic-scale silver contacts giving evidence for different individual-atom and electronic-shell configurations. The histogram was obtained from >21000 conductance

Distinction of nucleobases – a tip-enhanced Raman approach

• Regina Treffer,
• Xiumei Lin,
• Elena Bailo,
• Tanja Deckert-Gaudig and
• Volker Deckert

Beilstein J. Nanotechnol. 2011, 2, 628–637, doi:10.3762/bjnano.2.66

• found, and consequently a sequence-specific detection is only restricted by the lateral resolution and ultimately by the signal-to-noise ratio of the spectra recorded at subsequent positions. Conclusion Our results present several important steps towards a direct and label-free sequencing of RNA/DNA

Femtosecond time-resolved photodissociation dynamics of methyl halide molecules on ultrathin gold films

• Mihai E. Vaida,
• Robert Tchitnga and
• Thorsten M. Bernhardt

Beilstein J. Nanotechnol. 2011, 2, 618–627, doi:10.3762/bjnano.2.65

• single transients were averaged to improve the signal-to-noise ratio. The transient was obtained with 2 mW/cm² pump (266 nm) and 200 mW/cm² probe (333 nm) laser power. Intensity of the CH3+ signal as a function of (a) pump power and (b) probe power. Both measurements (a) and (b) were performed for a pump

Room temperature excitation spectroscopy of single quantum dots

• Christian Blum,
• Frank Schleifenbaum,
• Martijn Stopel,
• Sébastien Peter,
• Marcus Sackrow,
• Vinod Subramaniam and
• Alfred J. Meixner

Beilstein J. Nanotechnol. 2011, 2, 516–524, doi:10.3762/bjnano.2.56

• devices. The primary challenge has been the intrinsic difficulty in measuring the absorption of a single emitter at room temperature due to the extremely low signal to noise ratio. Although recent reports have demonstrated the detection of single molecule absorbance [25][26][27], a complete single

Tip-enhanced Raman spectroscopic imaging of patterned thiol monolayers

• Johannes Stadler,
• Thomas Schmid,
• Lothar Opilik,
• Phillip Kuhn,
• Petra S. Dittrich and
• Renato Zenobi

Beilstein J. Nanotechnol. 2011, 2, 509–515, doi:10.3762/bjnano.2.55

• enhancement can in principle be reached. An attempt was made to visualize the distribution of molecules using SERS, but this did not yield satisfactory results. However, the large signal-to-noise ratio in every pixel of a TERS image allows one to obtain enough information to distinguish a full monolayer from

• each TERS map, laser power and exposure time per spectrum were adapted according to the enhancement of the tip and the activity of the analyte. The laser power used ranged between 0.1–2.0 mW and collection times of 0.1–2.0 s per spectrum were chosen to yield a sufficient signal-to-noise ratio for the

Simulation of bonding effects in HRTEM images of light element materials

• Simon Kurasch,
• Jannik C. Meyer,
• Daniela Künzel,
• Axel Groß and
• Ute Kaiser

Beilstein J. Nanotechnol. 2011, 2, 394–404, doi:10.3762/bjnano.2.45

• remains stable enough under the electron beam to obtain a sufficient high signal to noise ratio, this might be achievable by applying higher defocus (see second row in Figure 10) or a phase plate (see third row in Figure 10). Conclusion We presented a practical method to include chemical bonding in the

Effect of large mechanical stress on the magnetic properties of embedded Fe nanoparticles

• Srinivasa Saranu,
• Sören Selve,
• Ute Kaiser,
• Luyang Han,
• Ulf Wiedwald,
• Paul Ziemann and
• Ulrich Herr

Beilstein J. Nanotechnol. 2011, 2, 268–275, doi:10.3762/bjnano.2.31

• films, each bit comprises a large number of magnetic grains, which are coupled by dipolar interactions and, to some extent, by inter granular exchange coupling. The necessity for incorporation of many grains in each bit arises from the requirement for a sufficiently large signal-to-noise ratio. A

Extended X-ray absorption fine structure of bimetallic nanoparticles

• Carolin Antoniak

Beilstein J. Nanotechnol. 2011, 2, 237–251, doi:10.3762/bjnano.2.28

•  2. In this case, the data have to be multiplied by a window function W since for low values of k (XANES regime) the resonant absorption dominates the scattering effects, and for high values of k the signal-to-noise ratio becomes too small. The data are shown only in the region of non-vanishing

Single-pass Kelvin force microscopy and dC/dZ measurements in the intermittent contact: applications to polymer materials

• Sergei Magonov and
• John Alexander

Beilstein J. Nanotechnol. 2011, 2, 15–27, doi:10.3762/bjnano.2.2

• nanotubes probes (generously provided by Carbon Design Innovations). The probes with small tip apex and tips with high aspect ratio provide higher spatial resolution of surface potential images whereas the probes with thicker tips have a better signal-to-noise ratio of the surface potential. The majority of

• images obtained in both regimes. The signal-to-noise ratio of the surface potential pattern is higher in the intermittent contact operation due to the larger dC/dZ amplitude in immediate vicinity of the sample. A higher spatial resolution of the surface potential image obtained in the intermittent

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

• oscillation amplitude of the tuning fork. The signal is so small that a low-temperature amplifier has to be placed nearby to improve the signal-to-noise ratio. In NC-AFM, the shift of the tuning fork resonance frequency Δf is used as a feedback signal to scan with constant Δf. The tip is electrically

Magnetic nanoparticles for biomedical NMR-based diagnostics

• Huilin Shao,
• Tae-Jong Yoon,
• Monty Liong,
• Ralph Weissleder and
• Hakho Lee

Beilstein J. Nanotechnol. 2010, 1, 142–154, doi:10.3762/bjnano.1.17

• measurements, and each microcoil held 5–10 μl of sample. In the second-generation μNMR, we changed our design to solenoidal coils [15][16], as such geometry provides higher signal-to-noise ratio (SNR) by producing more homogeneous radio-frequency magnetic fields for sample excitation. The SNR could be further

• factor, better signal-to-noise ratio, and reduced sample volume requirement to ~1 μL. (c) The latest 0.1 kg “palm” DMR system is 20× lighter and 30× smaller than previous generations. To achieve this significant size reduction, a small 0.56 T magnet was used. To compensate for the signal reduction from

Preparation and characterization of supported magnetic nanoparticles prepared by reverse micelles

• Ulf Wiedwald,
• Luyang Han,
• Johannes Biskupek,
• Ute Kaiser and
• Paul Ziemann

Beilstein J. Nanotechnol. 2010, 1, 24–47, doi:10.3762/bjnano.1.5

• for the XPS spectra. For example, to arrive at a reasonable signal-to-noise ratio for the Co-2p peaks, a data acquisition time of 12 h is required. Even under UHV conditions such a long exposure of a sample surface to X-rays results in the built-up of a small amount of carbon contamination, which, by