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

• frequency of fc = 1 kHz is used in the LIA. The ND estimates are shown in Figure 8a which are obtained from the time-domain demodulated amplitude signals sampled at 28.8 kHz using Welch’s segment averaging estimator with 8 sections windowed with the Hamming window. The results are summarized in Table 2. It

Current-induced runaway vibrations in dehydrogenated graphene nanoribbons

• Rasmus Bjerregaard Christensen,
• Jing-Tao Lü,
• Per Hedegård and
• Mads Brandbyge

Beilstein J. Nanotechnol. 2016, 7, 68–74, doi:10.3762/bjnano.7.8

• phonon l. The SGLE, in Equation 1, is given in the time domain. However, since we are considering steady state, it is convenient to work in the frequency domain. Thus, by Fourier transformation we obtain, By applying the Sokhatsky–Weierstrass theorem Πr(ω) can be split into four contributions giving rise

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

• between each individual SLS element and the tip, and d is the distance between element j and the tip surface. The amplitude and phase of each eigenmode were calculated using the in-phase (Ii) and quadrature (Ki) integrals: where zi(t) is the eigenmode response in the time domain, as in Equation 1, N is

A single-source precursor route to anisotropic halogen-doped zinc oxide particles as a promising candidate for new transparent conducting oxide materials

• Daniela Lehr,
• Markus R. Wagner,
• Johanna Flock,
• Julian S. Reparaz,
• Clivia M. Sotomayor Torres,
• Alexander Klaiber,
• Thomas Dekorsy and
• Sebastian Polarz

Beilstein J. Nanotechnol. 2015, 6, 2161–2172, doi:10.3762/bjnano.6.222

• from the sample. Time-domain THz spectroscopy was performed with a custom-build transmission setup employing asynchronous optical sampling (ASOPS) with two frequency-locked femtosecond Ti:sapphire lasers with repetition rates of one GHz [56][57]. The data were partially evaluated with the commercial

• portion of grain boundaries. To get further information about the influence of doping on the conductivity, measurements of the complex dielectric function in the THz frequency range were performed. Time-domain THz spectroscopy [56][57] is a method to investigate the transmission and/or reflection of a

• sample in the THz frequency range. The transmitted electric field is directly sampled in the time domain, which provides amplitude and phase information of the transmission spectrum. A comparison with a reference measurement allows for the calculation of the complex dielectric function ε(w) of the sample

Near-field visualization of plasmonic lenses: an overall analysis of characterization errors

• Jing Wang,
• Yongqi Fu,
• Zongwei Xu and
• Fengzhou Fang

Beilstein J. Nanotechnol. 2015, 6, 2069–2077, doi:10.3762/bjnano.6.211

• on the basis of a finite-difference and time-domain (FDTD) algorithm so as to support the error analyses. The analyses performed on the basis of both theoretical calculation and experimental probing can provide a helpful reference for the researchers probing their plasmonic structures and

• intensity profiles of the electric field for plasmonic lenses with different ratios σ under plane wave illumination. The working wavelength of the lenses is 532 nm. Three dimensional (3D) calculations were carried out on the basis of finite-difference and time-domain (FDTD) algorithm. The elliptical ratio

Large-voltage behavior of charge transport characteristics in nanosystems with weak electron–vibration coupling

• Tomáš Novotný and
• Wolfgang Belzig

Beilstein J. Nanotechnol. 2015, 6, 1853–1859, doi:10.3762/bjnano.6.188

• cumulants. However, the direct calculation of higher-order cumulants in the time domain is a rather complicated procedure. Instead, we can use a simple trick combining the master equation for the oscillator with the relation between the current and thus also passed charge . Since the charge Qinel(t) is a

Attenuation, dispersion and nonlinearity effects in graphene-based waveguides

• Almir Wirth Lima Jr.,
• João Cesar Moura Mota and
• Antonio Sergio Bezerra Sombra

Beilstein J. Nanotechnol. 2015, 6, 1221–1228, doi:10.3762/bjnano.6.125

• P0 = 10−10 W, λ0 = 1.55 mm and μg = 0.80 eV. Notice that the shape of the Gaussian pulse in the time domain undergoes a small change, but the output Gaussian pulse in the frequency domain remains unchanged. In the upper part of Figure 8, the intensity, also calculated in accordance with Equation 8

• P0 = 10−9 W (λ0 = 1.55 μm, μg = 0.80 eV). From Figure 8, one can see that these pulses with P0 = 10−9 W suffer a moderate change in the time domain, but they are not changed in the frequency domain. After several simulations, we concluded that given the same propagation length, an increase in the

• distort the shape of the Gaussian pulse in the time domain at the nanophotonic waveguide output. To conclude our simulations regarding graphene-based nanophotonic waveguides, we used a hyperbolic-secant-shaped pulse in the time domain. The results of the intensity (calculated according to Equation 8) as a

Improved optical limiting performance of laser-ablation-generated metal nanoparticles due to silica-microsphere-induced local field enhancement

• Zheren Du,
• Lianwei Chen,
• Tsung-Sheng Kao,
• Mengxue Wu and
• Minghui Hong

Beilstein J. Nanotechnol. 2015, 6, 1199–1204, doi:10.3762/bjnano.6.122

• the finite-difference time-domain (FDTD) method with the Lumerical software for predicting the enhancement of the optical nonlinearity by the microspheres. The refractive index of the environment (water) was set at 1.33, while the refractive index of the silica microsphere was set at 1.51. It is

Exploring plasmonic coupling in hole-cap arrays

• Thomas M. Schmidt,
• Maj Frederiksen,
• Vladimir Bochenkov and
• Duncan S. Sutherland

Beilstein J. Nanotechnol. 2015, 6, 1–10, doi:10.3762/bjnano.6.1

• The plasmonic coupling between gold caps and holes in thin films was investigated experimentally and through finite-difference time-domain (FDTD) calculations. Sparse colloidal lithography combined with a novel thermal treatment was used to control the vertical spacing between caps and hole arrays and

• -difference time-domain (FDTD) simulations. We show strong coupling of the dipolar and quadrupolar nanocap resonances with the Bloch wave-SPP (BW-SPP) and LSPR type hole array resonances. Experimental Nanostructure design Figure 1a shows a schematic of the design of the plasmonic gold structures fabricated by

• Nova 600 NanoLab XHR Magellan scanning electron microscope (SEM) from FEI generally with energies of 1–5 kV and nominal spot size ≈1 nm. Computer simulations of extinction spectra and charge/field plots analysis were carried out using the finite-difference time-domain method (FDTD Solutions, Lumerical

Modeling viscoelasticity through spring–dashpot models in intermittent-contact atomic force microscopy

• Enrique A. López-Guerra and
• Santiago D. Solares

Beilstein J. Nanotechnol. 2014, 5, 2149–2163, doi:10.3762/bjnano.5.224

• first eigenmode were calculated using the in-phase (Ii) and quadrature (Ki) terms: where zi(t) is the i-th eigenmode response in the time domain, N is the number of periods over which the phase and amplitude were averaged, ω is the excitation frequency, and τ is the fundamental period of one oscillation

Properties of plasmonic arrays produced by pulsed-laser nanostructuring of thin Au films

• Katarzyna Grochowska,
• Katarzyna Siuzdak,
• Peter A. Atanasov,
• Carla Bittencourt,
• Anna Dikovska,
• Nikolay N. Nedyalkov and
• Gerard Śliwiński

Beilstein J. Nanotechnol. 2014, 5, 2102–2112, doi:10.3762/bjnano.5.219

• -surrounding interface the finite-difference time-domain (FDTD) method represents a widely used tool. It allows for flexible modeling and effective problem solutions for isolated and simple particle systems, as well as for large particle populations and with interactions with the environment taken into account

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

• frequencies varied and are provided along with the results). The amplitude and phase of each eigenmode, where applicable, were calculated by using the in-phase (I) and quadrature (Q) integrals: where z(t) is the eigenmode response in the time domain, N is the number of periods over which the phase and

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

• : where zi(t) is the spatial response of the ith eigenmode in the time domain, N is the number of periods over which the phase and amplitude were averaged, ω is the excitation frequency, and τ is the nominal period of one oscillation. The amplitude (Ai) and phase () were calculated, respectively, as: The

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

• and phase of each eigenmode were calculated using the customary in-phase (Ii) and quadrature (Ki) terms: where zi(t) is the i-th eigenmode response in the time domain, N is the number of periods over which the phase and amplitude were averaged (we rounded N to the integer closest to 25 times the ratio

Methods for rapid frequency-domain characterization of leakage currents in silicon nanowire-based field-effect transistors

• Tomi Roinila,
• Xiao Yu,
• Jarmo Verho,
• Tie Li,
• Pasi Kallio,
• Matti Vilkko,
• Anran Gao and
• Yuelin Wang

Beilstein J. Nanotechnol. 2014, 5, 964–972, doi:10.3762/bjnano.5.110

• r(t)) disturb the measurements that can be now denoted by xe(t) and yr(t). The frequency-response function of the device can be denoted as where Y(jω) and X(jω) denote the Fourier transforms of the corresponding time-domain signals y(t) and x(t). In the presence of external noise the noise-affected

• into the SiNW FET through the current amplifier. Figure 10a shows a sample of the generated IRS in the time domain. Figure 10b shows the (scaled) power spectra. The voltage between the gate and drain was measured, together with the corresponding current. The device was assumed to maintain approximately

• FET device. The scale bar is 20 µm. Ids–Vds DC measurement results. Ids–Vg DC measurement results. Conceptual diagram of the measurement setup. Simplified schematic of the measurement amplifier. Generated excitation sequence; a) sample in the time domain, and b) (scaled) energy content. Admittance

Nanostructure sensitization of transition metal oxides for visible-light photocatalysis

• Hongjun Chen and
• Lianzhou Wang

Beilstein J. Nanotechnol. 2014, 5, 696–710, doi:10.3762/bjnano.5.82

• exhibit a much better photocatalytic performance than N-doped TiO2 nanoparticles or TiO2 nanotubes alone. Electromagnetic simulations based on the finite-difference time-domain method provided the theoretical support for this local electric field enhancement mechanism. In contrast to the local electric

Control theory for scanning probe microscopy revisited

• Julian Stirling

Beilstein J. Nanotechnol. 2014, 5, 337–345, doi:10.3762/bjnano.5.38

• preamplifier with a finite bandwidth. The logarithm of this output voltage is then taken either by a logarithmic amplifier or calculated numerically by the SPM controller. This results in a functional form for the time-domain operator action on the tunnel gap D(t) being where κ is the characteristic decay

• length of the tunnel junction, and is the time-domain operator corresponding to the transfer function in Equation 24. To calculate the s-space transfer function of Equation 26, one would need to calculate the Laplace transform of the exponential of an arbitrary function D(t). This may be possible for

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

• instabilities because the excitation of the cantilever is created from the real-time response of the cantilever, one cycle at a time. Figure 6 shows frequency and time domain second eigenmode responses obtained by sweeping the excitation frequency from low to high using chirp functions [35] while keeping the

• quality factor values in the range Q1 = 1–7, Q2 = 2Q1–3Q1; Q3 = 3Q1–5Q1. The equations of motion were integrated numerically and the amplitude and phase of each eigenmode were calculated using the customary in-phase (I) and quadrature (Q) terms: where z(t) is the eigenmode response in the time domain, N

Optical near-fields & nearfield optics

• Alfred J. Meixner and
• Paul Leiderer

Beilstein J. Nanotechnol. 2014, 5, 186–187, doi:10.3762/bjnano.5.19

• “optical antenna”. Since the fabrication of suitable structures with electron beam or focused ion beam lithography is a tedious and time-consuming task, the experiments are more and more supported by modeling with numerical methods such as Finite Difference Time Domain (FDTD) and Discrete Dipole

Friction behavior of a microstructured polymer surface inspired by snake skin

• Martina J. Baum,
• Lars Heepe and
• Stanislav N. Gorb

Beilstein J. Nanotechnol. 2014, 5, 83–97, doi:10.3762/bjnano.5.8

• skin from L. g. californiae and e) SIMPS based on AFM data. Results of frictional measurements on periodical groove-like polymer surface – PGMS perpendicular to the orientation of the microstructure. Left column, frictional signal in the spatial/time domain. Right column, frictional signal in the

• column, frictional signal in the spatial/time domain. Right column, frictional signal in the frequency domain after FFT; the ordinate shows the single-sided amplitude spectrum – SSAS. PGMS pitch dimension: a,b) 5 µm, c,d) 25 µm, e,f) 50 µm, g,h) 100 µm. Results of frictional measurements on randomly

• -rough surfaces – RRS. Left column, frictional signal in the spatial/time domain. Right column, frictional signal in the frequency domain after FFT; the ordinate shows the single-sided amplitude spectrum - SSAS. Grain size of RRS: a,b) 0.3 µm, c,d) 1 µm, e,f) 3 µm, g,h) 9 µm, i,j) 12 µm. Frequency

Dye-doped spheres with plasmonic semi-shells: Lasing modes and scattering at realistic gain levels

• Nikita Arnold,
• Boyang Ding,
• Calin Hrelescu and
• Thomas A. Klar

Beilstein J. Nanotechnol. 2013, 4, 974–987, doi:10.3762/bjnano.4.110

• dominates, irrespectively of the power of (a/λ) associated with it. Some of the higher modes may dominate simply because they best match the spectral bandwidth of the gain media. Numerical Here we summarize several subtleties, crucial for reliable simulations. Conventional finite difference time domain

Controlling the near-field excitation of nano-antennas with phase-change materials

• Tsung Sheng Kao,
• Yi Guo Chen and
• Ming Hui Hong

Beilstein J. Nanotechnol. 2013, 4, 632–637, doi:10.3762/bjnano.4.70

• conducted by the finite-difference-time-domain (FDTD) method (FDTD Solutions 8.5, Lumerical Inc.) with realistic material parameters and Joule loss factors [16][17]. The simulation model was established and is shown in the schematic diagram Figure 1. This near-field energy controllable system consists of

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

• measured at the parts of the surface with high stiffness (DMT). In contrast, a peak current (Figure 6f) was present in this area. The peak current signal gives the current flow at maximal pressure of the AFM tip (Δt ≈ 0.001 s). In this time domain, transient (capacitive) currents can be detected and were

k-space imaging of the eigenmodes of sharp gold tapers for scanning near-field optical microscopy

• Martin Esmann,
• Simon F. Becker,
• Bernard B. da Cunha,
• Jens H. Brauer,
• Ralf Vogelgesang,
• Petra Groß and
• Christoph Lienau

Beilstein J. Nanotechnol. 2013, 4, 603–610, doi:10.3762/bjnano.4.67

• several tens of microns on the surface of a gold taper [11]. These results have been confirmed by three-dimensional finite difference time domain (FDTD) simulations [11]. These theoretical investigations and experimental demonstrations suggest that pump–probe studies employing adiabatic nanofocusing are

Mapping of plasmonic resonances in nanotriangles

• Simon Dickreuter,
• Julia Gleixner,
• Andreas Kolloch,
• Johannes Boneberg,
• Elke Scheer and
• Paul Leiderer

Beilstein J. Nanotechnol. 2013, 4, 588–602, doi:10.3762/bjnano.4.66

• approximation (DDA) or finite-difference in the time-domain (FDTD). Secondly, the outcome of these simulations has to be compared to a measurement of the field distribution. Since the field enhancement can be highly confined, direct probing of the field distribution is rather challenging. Experimental