Free and partially encapsulated manganese ferrite nanoparticles in multiwall carbon nanotubes

• Saja Al-Khabouri,
• Salim Al-Harthi,
• Toru Maekawa,
• Mohamed E. Elzain,
• Ashraf Al-Hinai,
• Ahmed D. Al-Rawas,
• Abbsher M. Gismelseed,
• Ali A. Yousif and
• Myo Tay Zar Myint

Beilstein J. Nanotechnol. 2020, 11, 1891–1904, doi:10.3762/bjnano.11.170

• at 77 K, using a Mössbauer spectrometer in constant-acceleration mode with 50 mC 57Co in a Rh source. Results and Discussion Free MnFe2O4 nanoparticles The XRD patterns were analyzed using the MAUD (material analysis using diffraction) fitting software based on the Rietveld method and on Fourier

• analysis. The analysis was carried out to obtain the crystallite size and lattice parameters. For that, a pseudo-Voigt peak-shape profile was used in which an iterative least-square procedure was adopted through the minimization of the residual parameters [13]. X-ray diffraction data (Figure 1a) confirmed

Current measurements in the intermittent-contact mode of atomic force microscopy using the Fourier method: a feasibility analysis

• Berkin Uluutku and
• Santiago D. Solares

Beilstein J. Nanotechnol. 2020, 11, 453–465, doi:10.3762/bjnano.11.37

• discuss a possible approach to develop an intermittent-contact conductive AFM mode based on Fourier analysis, whereby the measured current response consists of higher harmonics of the cantilever oscillation frequency. Such an approach may enable the characterization of soft samples with less damage than

• ; intermittent contact; Fourier analysis; tapping-mode AFM; Introduction Conductive atomic force microscopy (C-AFM), a contact-mode technique, has been extensively utilized to investigate local electrical properties of nanoscale systems, such as organic solar cells [1][2][3][4][5][6][7], semiconductors [8][9

• Fourier analysis to implement ICM current measurements. Fourier analysis is commonly used in ICM-AFM experiments due to the periodic nature of the cantilever excitation and response. For example, in amplitude-modulation AFM (AM-AFM), the most common ICM-AFM method, a lock-in amplifier is used to track the

Nematic liquid crystal alignment on subwavelength metal gratings

• Irina V. Kasyanova,
• Artur R. Geivandov,
• Vladimir V. Artemov,
• Maxim V. Gorkunov and
• Serguei P. Palto

Beilstein J. Nanotechnol. 2018, 9, 42–47, doi:10.3762/bjnano.9.6

• , Russia 10.3762/bjnano.9.6 Abstract We have studied the alignment of a nematic liquid crystal (LC) material on aluminum subwavelength nanogratings as a function of the period, p, and the slit width to period ratio, w/p. A method, based on Fourier analysis of the transmittance spectra of the LC grating

• have also obtained a 90° twisted LC director distribution, implying sufficiently strong azimuthal LC anchoring at the grating surface. Keywords: alignment; Fourier analysis; nematic liquid crystal; subwavelength metal grating; Introduction In the age of nanotechnology, various nanostructured

• conclude that there is a hybrid or inhomogeneous alignment, as in the case shown in Figure 3b, where two domains with different pretilt angles coexist. We present the results of Fourier analysis only for the gratings; in the case of gratings, where the twisted alignment takes place, the input

Velocity dependence of sliding friction on a crystalline surface

• Christian Apostoli,
• Giovanni Giusti,
• Jacopo Ciccoianni,
• Gabriele Riva,
• Rosario Capozza,
• Rosalie Laure Woulaché,
• Andrea Vanossi,
• Emanuele Panizon and
• Nicola Manini

Beilstein J. Nanotechnol. 2017, 8, 2186–2199, doi:10.3762/bjnano.8.218

• nature we understand by means of a Fourier analysis of the excited phonon modes. By relating the phonon phase velocities with the slider velocity, we obtain an equation whose solutions predict which phonons are being excited by the slider moving at a given speed. Keywords: atomic-scale friction; contact

Angstrom-scale flatness using selective nanoscale etching

• Takashi Yatsui,
• Hiroshi Saito and
• Katsuyuki Nobusada

Beilstein J. Nanotechnol. 2017, 8, 2181–2185, doi:10.3762/bjnano.8.217

• molecules. ONFs selectively generated at the apex of protrusions on the surface selectively etch the protrusions. To confirm the selective etching of the nanoscale structure, we compared near-field etching using both gas molecules and ions in liquid phase. Using two-dimensional Fourier analysis, we found

• the etching characteristics using a two-dimensional Fourier analysis. Experimental Nanoscale etching For dry etching, we used Cl2 gas at a pressure of 200 Pa. 25 wt % calcium hypochlorous acid (Ca(ClO)2) was used as the source ion for wet etching. To dissociate the Cl2 or hypochlorous acid, we used a

• -field dry etching, because of a greater MFP value of the gas phase that exceeds the scanning area, the dissociated atoms can react only when they are located at the protrusions where the ONF generated. Conclusion Using two-dimensional Fourier analysis, we found that near-field etching is effective for

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

• spectral response, the main frequency components are given by the trap’s base frequency ωy = 2π × 70 Hz and its first harmonic. However, the Fourier analysis reveals some minor deviations between simulations and measurement, as the experimental data show minor contributions also at the other trap

Polynomial force approximations and multifrequency atomic force microscopy

• Daniel Platz,
• Daniel Forchheimer,
• Erik A. Tholén and
• David B. Haviland

Beilstein J. Nanotechnol. 2013, 4, 352–360, doi:10.3762/bjnano.4.41

• approximative reconstruction method applied to spectral data obtained from Fourier analysis of the tip motion. The general idea, to determine the parameters of a force model such that an experimental observable is best approximated, is not limited to spectral data. An alternative to the spectral representation

Towards 4-dimensional atomic force spectroscopy using the spectral inversion method

• Jeffrey C. Williams and
• Santiago D. Solares

Beilstein J. Nanotechnol. 2013, 4, 87–93, doi:10.3762/bjnano.4.10

• frequency. In order to obtain a 4D representation of the tip–sample forces, it is necessary to also measure the tip velocity in real time, which can be easily recovered from the flexural position, zc(t) (again, neglecting zp(t)), by using the well-known property of Fourier analysis that states that where

• spectral inversion method from three to four dimensions are relatively minor, since the tip position data is already recorded. Furthermore, all Fourier analysis is carried out during a post-processing step and the calculation of the velocity does not represent an excessive computational burden. Thus, the

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

• fundamental mode. To clarify the influence of the higher eigenmode oscillation on the image quality, the amplitude ratio of both modes was systematically varied. Fourier analysis of the time series recorded during imaging showed frequency mixing. However, these spurious signals were at least two orders of

•  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

• transform was calculated from the material contrast (d). (a) Bimodal AFM deflection signal and (b) Fourier analysis of the time trace obtained for the SB sample surface. (a) In the time trace, the oscillations are sinusoidal at both eigenmodes. (b) The Fourier transform reveals mechanical mixing between the

Wavelet cross-correlation and phase analysis of a free cantilever subjected to band excitation

• Francesco Banfi and
• Gabriele Ferrini

Beilstein J. Nanotechnol. 2012, 3, 294–300, doi:10.3762/bjnano.3.33

• important to note that the phase relations just described refer to a frequency band that has been simultaneously excited and encompasses the resonant frequency. Although the above description of the spectral phase appears intuitive, it would not be possible to obtain it by means of a classical Fourier

• analysis. If the signal is not stationary, as is the case in band excitation, the squared magnitude of the Fourier coefficients measure the average energy contained in a spectral interval without tracing its effective time evolution. In this case the phase relative to each spectral component is not “local

Tip-sample interactions on graphite studied using the wavelet transform

• Giovanna Malegori and
• Gabriele Ferrini

Beilstein J. Nanotechnol. 2010, 1, 172–181, doi:10.3762/bjnano.1.21

• excited cantilever to get insights into fundamental thermodynamical properties of its motion. The shortcomings of the widely used Fourier analysis are briefly discussed to put into perspective the wavelet transform analysis, used to describe the temporal evolution of the spectral content of the thermal

• oscillations collected at different separations from the surface. Successively the CWT and its use in DFS will be introduced. Fourier analysis of the cantilever thermal fluctuations Fourier analysis can be used to process the temporal trace of the cantilever thermal vibrations detected by a standard AFM

• . Instead, a time-frequency representation shows the signal evolution over both time and frequency. CWT is a refined alternative to the classical windowed Fourier analysis, providing not only the representation of the spectral energy content of the signal at a certain time, but also the ability to adapt the