Structural and optical characteristics determined by the sputtering deposition conditions of oxide thin films

• Petronela Prepelita,
• Florin Garoi and
• Valentin Craciun

Beilstein J. Nanotechnol. 2021, 12, 354–365, doi:10.3762/bjnano.12.29

• diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), while the surface topography of the samples was analyzed using scanning electron microscopy (SEM). The optical characteristics were measured for samples with the same composition but obtained with different deposition parameters, such as increasing

The patterning toolbox FIB-o-mat: Exploiting the full potential of focused helium ions for nanofabrication

• Victor Deinhart,
• Lisa-Marie Kern,
• Jan N. Kirchhof,
• Sabrina Juergensen,
• Joris Sturm,
• Enno Krauss,
• Thorsten Feichtner,
• Sviatoslav Kovalchuk,
• Michael Schneider,
• Dieter Engel,
• Bastian Pfau,
• Bert Hecht,
• Kirill I. Bolotin,
• Stephanie Reich and
• Katja Höflich

Beilstein J. Nanotechnol. 2021, 12, 304–318, doi:10.3762/bjnano.12.25

• patterning without affecting the topography of the films [32]. The local modification of the magnetic properties, in particular anisotropy and exchange coupling (including the chiral Dzyaloshinskii–Moriya interaction), originates from structural modifications, such as interface structure, atomic ordering

• curvatures in the beam path, use the local dose optimization to achieve a uniform target depth. To demonstrate the capabilities of FIB-o-mat, three different 2D material systems were patterned. Multilayers of Co/Pt were modified regarding their local magnetic response without changing their topography

The nanomorphology of cell surfaces of adhered osteoblasts

• Christian Voelkner,
• Mirco Wendt,
• Regina Lange,
• Max Ulbrich,
• Martina Gruening,
• Susanne Staehlke,
• Barbara Nebe,
• Ingo Barke and
• Sylvia Speller

Beilstein J. Nanotechnol. 2021, 12, 242–256, doi:10.3762/bjnano.12.20

• flexible. Figure 2a shows an example of a typical SICM topography of the border region in the live state (see Figure 2b for the corresponding bright-field microscopy image). Features with lateral dimensions of approximately 1 µm × 0.8 µm protruding 100–300 nm from the surrounding (Figure 2c), at a density

• when the live-cell dynamics is suppressed upon fixation of the osteoblasts with 4% paraformaldehyde (PFA). Figure 3a shows an example of a respective SICM topography. Now, the ruffles exhibit a clearer shape and resemble similar features to those observed with electron microscopy [29][30]. Our data

• area (Aeff – Aproj). The effective surface is the undulated surface area of the three-dimensional function z(x,y) as determined from SICM topography images, and the projected area is the frame or base area Aproj = ∫∫dxdy (Figure 5b). The relative excess surface is then Figure 5a shows the relative

Extended iron phthalocyanine islands self-assembled on a Ge(001):H surface

• Rafal Zuzak,
• Marek Szymonski and
• Szymon Godlewski

Beilstein J. Nanotechnol. 2021, 12, 232–241, doi:10.3762/bjnano.12.19

• manipulation when the molecule marked by the dashed circle suddenly appeared on a perfectly hydrogenated Ge(001):H surface area. This could be inferred from that fact that the image shows the molecule only in the upper part of the scan, whereas the lower part of the topography presents the perfectly

Imaging of SARS-CoV-2 infected Vero E6 cells by helium ion microscopy

• Natalie Frese,
• Patrick Schmerer,
• Martin Wortmann,
• Matthias Schürmann,
• Matthias König,
• Michael Westphal,
• Friedemann Weber,
• Holger Sudhoff and
• Armin Gölzhäuser

Beilstein J. Nanotechnol. 2021, 12, 172–179, doi:10.3762/bjnano.12.13

• topography or material contrast. The deposited carbon film is presumably thinner than typical conductive metal or carbon coatings for SEM imaging, and it does not show any surface masking and clustering as seen on the gold substrate in the upper left of Figure 2b2. The energy of the incident hydrocarbons is

• observed for human coronavirus229E and quantified in HeLa cells by Wang and co-workers [38]. However, the metal coating applied by Wang et al. is clearly visible at high resolution in the SEM images as a rough layer on the cell membrane that hides the true topography [25][39]. In contrast, the HIM images

Mapping the local dielectric constant of a biological nanostructured system

• Wescley Walison Valeriano,
• Rodrigo Ribeiro Andrade,
• Juan Pablo Vasco,
• Angelo Malachias,
• Bernardo Ruegger Almeida Neves,
• Paulo Sergio Soares Guimarães and
• Wagner Nunes Rodrigues

Beilstein J. Nanotechnol. 2021, 12, 139–150, doi:10.3762/bjnano.12.11

• double-pass mode, which means that the probe executes two scans. The first scan measures the sample topography in tapping mode and the second scan mimics the profile at a defined lift height Zlift applying a voltage VDC between the tip and the conductive substrate [21]. The tip is mechanically forced to

• ). The α coefficient map and its average profile differ slightly from the topographic information, but some correspondences are identified. Thicker regions have a smaller α coefficient, as can be seen at the wing–resin interface (Figure 5b). There seems to be a correlation between topography (Figure 5a

• ) and the relative permittivity εr (Figure 5c): the lower the topography, the larger the εr. However, we observe a small εr value in the lower topography regions adjacent to the wing slab. Hence, topography crosstalk is small. Chalcopterix rutilans damselfly wings Using the protocol described above, we

Fusion of purple membranes triggered by immobilization on carbon nanomembranes

• René Riedel,
• Natalie Frese,
• Fang Yang,
• Martin Wortmann,
• Raphael Dalpke,
• Daniel Rhinow,
• Norbert Hampp and
• Armin Gölzhäuser

Beilstein J. Nanotechnol. 2021, 12, 93–101, doi:10.3762/bjnano.12.8

• topography data from the first scan. The voltage applied to the tip to compensate for attracting/repelling electrostatic forces indicates the electrostatic potential of the sample. The samples were further analyzed by SEM in a Zeiss Auriga (Carl Zeiss, Jena, Germany) at an acceleration voltage of 5 kV using

• samples were subsequently washed with 200 µL distilled water and dried in a nitrogen flow. For each sample the topography of a 50 × 50 µm2 area was investigated by AFM to evaluate substrate coverage. It has been shown that the WT PM patches do not form a continuous monolayer, but rather separately

Bulk chemical composition contrast from attractive forces in AFM force spectroscopy

• Dorothee Silbernagl,
• Media Ghasem Zadeh Khorasani,
• Natalia Cano Murillo,
• Anna Maria Elert and
• Heinz Sturm

Beilstein J. Nanotechnol. 2021, 12, 58–71, doi:10.3762/bjnano.12.5

• material phases based on AFM topography. Additional chemical characterization on the nanoscale is performed by an AFM/infrared-spectroscopy hybrid method. Mechanical properties (kr) and attractive forces (Fattr) are calculated and a structure–property correlation is obtained by a manual principle component

• and material interphases are usually deduced from AFM topography. This is problematic because subsurface structures are not taken into consideration even though they might be relevant for the physical properties [2][15]. Also, with increasing resolution and decreasing size of heterogeneous structures

• , AFM topography is often not conclusive. To overcome these disadvantages, complementary measurements are performed. Methods such as SEM and EDX are able to image structural contrasts with a lateral resolution on the order of magnitude of the AFM tip size or higher [16][17][18][19]. However, since those

Atomic layer deposited films of Al₂O₃ on fluorine-doped tin oxide electrodes: stability and barrier properties

• Hana Krýsová,
• Michael Neumann-Spallart,
• Hana Tarábková,
• Pavel Janda,
• Ladislav Kavan and
• Josef Krýsa

Beilstein J. Nanotechnol. 2021, 12, 24–34, doi:10.3762/bjnano.12.2

• deposited Al2O3. The height-density distribution (Figure S2, Supporting Information File 1), calculated from the AFM topography images (Figure 1), shows that the deposition of Al2O3 onto FTO substrates does not change its surface morphology. Calculated RMS (root mean square) values for AFM images of FTO and

• protection against the reduction of FTO. While bare FTO was reduced to Sn at −1.2 V vs Ag/AgCl in a neutral electrolyte, the Al2O3-coated FTO became reduction-resistant. AFM topography image (10 µm × 10 µm) of an FTO substrate (left) and of an FTO substrate coated with a 17 nm thick Al2O3 layer (right

Bio-imaging with the helium-ion microscope: A review

• Matthias Schmidt,
• James M. Byrne and
• Ilari J. Maasilta

Beilstein J. Nanotechnol. 2021, 12, 1–23, doi:10.3762/bjnano.12.1

• SEMs (FE-SEM) and transmission electron microscopes (TEM). On the other hand, HIM is less demanding in terms of sample preparation compared to both SEM and TEM. In particular, the advantage of HIM is that opaque and non-conductive specimens, which possess a relatively strong topography, can be imaged

• reach the detector. In HIM, the emitted secondary electrons already have low energy, which results in a strong edge and topography contrast. Furthermore, the low energies of the secondary electrons in a HIM produce excellent contrast due to changes in the work functions of the materials. An interesting

• EPS. The micrograph was recorded using secondary electron imaging. The high surface sensitivity and the strongly pronounced edges in this imaging mode render the thin EPS between the algal cells bright white. Furthermore, it is remarkable that despite the strong topography of more than 20 μm in the

Mapping of integrated PIN diodes with a 3D architecture by scanning microwave impedance microscopy and dynamic spectroscopy

• Rosine Coq Germanicus,
• Peter De Wolf,
• Florent Lallemand,
• Catherine Bunel,
• Serge Bardy,
• Hugues Murray and
• Ulrike Lüders

Beilstein J. Nanotechnol. 2020, 11, 1764–1775, doi:10.3762/bjnano.11.159

• 90 kHz and VDC = 0 V. The signals of ∂C/∂V phase, ∂C/∂V amplitude, sMIM-R, sMIM-C, and the topography were simultaneously acquired. In a second investigation, dynamic sMIM spectroscopy was performed by sweeping the VDC voltage from −2.0 V to 2.5 V at each location of the scan. The Integrated PIN

• , an electrical back contact is created between the microscope chuck and the sample. Results and Discussion The vertical PIN structure Figure 2 shows the surface topography of the cross section of the PIN diode. The different materials used (silicon substrate, epitaxial layers, oxides, and alloy metals

• ) have a slightly different polishing rate, which results in the observed topography. In the AFM topography image, one can localize the two deep trench isolation structures in the silicon wafer, as well as the anode and cathode contacts. It is important to note that a low roughness is required for a

Direct observation of the Si(110)-(16×2) surface reconstruction by atomic force microscopy

• Tatsuya Yamamoto,
• Ryo Izumi,
• Kazushi Miki,
• Takahiro Yamasaki,
• Yasuhiro Sugawara and
• Yan Jun Li

Beilstein J. Nanotechnol. 2020, 11, 1750–1756, doi:10.3762/bjnano.11.157

• cantilever was used, which was cleaned by Ar+ sputtering to remove the oxide and contamination on the tip. The deflection of the cantilever was measured by the optical beam deflection method. The topography of the surface was imaged while feedback electronics were used to adjust the tip–sample distance to

• images [37], these five bright spots can be explained by the dangling bonds of five atoms. Therefore, it was concluded that the five bright spots in pentagonal formation observed for a negative tip bias in STM images correspond to five atoms, that is, they were not due to crosstalk between the topography

Application of contact-resonance AFM methods to polymer samples

• Sebastian Friedrich and
• Brunero Cappella

Beilstein J. Nanotechnol. 2020, 11, 1714–1727, doi:10.3762/bjnano.11.154

• topography image of a 100 nm thick PnBMA film scanned with a PPP-FMAuD cantilever (kc = 2.74 N/m). The wave pattern was “engraved” into a smaller scan area of (15 µm)2 in DART mode previous to the scan in tapping mode. For the DART scan a static force of 308 nN, a frequency of ca. 320 kHz, and amplitudes of

• tip radius R was measured through recording tapping mode topography images on a grid with sharp tips (see Experimental section). The curves can be fitted quite exactly, most of all those on glass and PS. The three values of the reduced elastic moduli obtained for glass, PMMA, and PS are 62.3 GPa, 9.4

• topography image of a 100 nm thick PnBMA film after a smaller area (15 µm)2 was scanned in DART mode with a static force of 308 nN, a frequency of ca. 320 kHz, and amplitudes of 440 and 80 pm. CR frequency f(t) in the first mode as a function of the measuring time on three PnBMA films with thickness of 25

PTCDA adsorption on CaF₂ thin films

• Philipp Rahe

Beilstein J. Nanotechnol. 2020, 11, 1615–1622, doi:10.3762/bjnano.11.144

• different surface areas. Imaging of PTCDA on a Si(111)-(7 × 7) cornerhole position at (a) negative and (d) positive sample bias (sample bias indicated in the upper right corner). (b) Topography-mode image at negative bias and (e) constant-height mode imaging at positive bias of PTCDA on a CaF1/Si(111

• in (c). The topography image in (d) presenting PTCDA on a mixed CaF2 and CaF1/Si(111) surface is used for the statistical analysis in (b). STM data acquired on a CaF1/Si(111) surface area (e) before and (f) after accidental removal of single PTCDA molecules by the STM tip. Stationary molecules are

Design of V-shaped cantilevers for enhanced multifrequency AFM measurements

• Mehrnoosh Damircheli and
• Babak Eslami

Beilstein J. Nanotechnol. 2020, 11, 1525–1541, doi:10.3762/bjnano.11.135

• -pass measurement [1]. In bimodal AFM, the first eigenmode is excited at or near the resonance frequency (reserved for topography measurements) while the second eigenmode is in open-loop capturing material composition via phase shift of the second eigenmode. Due to its unique capabilities

• surface. The second sample is a polymer blend of PS and low-density polyethylene (LDPE) (HarmoniX sample purchased from Bruker) in order to challenge the cantilevers with more similar material properties. Figure 13a–c shows height or topography images of the Au–PS sample imaged in bimodal AFM using a

•  13a–c shows relatively similar topographies, Figure 13f show the highest phase contrast between Au and PS for the short V-shaped cantilever. Figure 14a–c shows height or topography images of the PS–LDPE samples imaged using a rectangular, a long V-shaped, and a short V-shaped cantilever, respectively

Helium ion microscope – secondary ion mass spectrometry for geological materials

• Matthew R. Ball,
• Richard J. M. Taylor,
• Joshua F. Einsle,
• Fouzia Khanom,
• Christelle Guillermier and
• Richard J. Harrison

Beilstein J. Nanotechnol. 2020, 11, 1504–1515, doi:10.3762/bjnano.11.133

• substitute in the crystal lattice within a solid solution. The Li signal appears to be stronger along mica sheets perpendicular to the c-axis of the crystal structure. However, this may be the result of surface topography similar to that observed in the zircon samples, as a result of polishing picking out

Protruding hydrogen atoms as markers for the molecular orientation of a metallocene

• Linda Laflör,
• Michael Reichling and
• Philipp Rahe

Beilstein J. Nanotechnol. 2020, 11, 1432–1438, doi:10.3762/bjnano.11.127

• with respect to the CaF2(111) surface lattice differs for the two geometries. In this work we investigate the NC-AFM contrast formation of FDCA molecules on CaF2(111) surfaces. A distinct dumbbell shape has been observed in both topography and constant-height imaging modes in low-temperature

• passes a molecular protrusion. Dumbbell shape of single FDCA molecules. Quadruped binding motif of FDCA on CaF2(111) (adapted from [22]) of (a) geo 1 and (b) geo 2. Dumbbell shape of FDCA molecules (c) on bulk CaF2(111) measured by NC-AFM in topography mode and (d) on thin film CaF2(111) surface measured

• frequency shift image. An inverted colour scale is used for the constant-height Δf NC-AFM data to match the topography appearance.) High-resolution NC-AFM imaging and simulation. Experimental and simulated frequency-shift images of a single molecular row along the direction (red arrows). Exemplary

Atomic defect classification of the H–Si(100) surface through multi-mode scanning probe microscopy

• Jeremiah Croshaw,
• Thomas Dienel,
• Taleana Huff and
• Robert Wolkow

Beilstein J. Nanotechnol. 2020, 11, 1346–1360, doi:10.3762/bjnano.11.119

• concentration of dihydrides can be controlled by lowering the annealing temperature during sample preparation [19][70]. While the two varieties of dihydride look unique overall in STM empty states topography (Figure 2d-1 and Figure 2e-1), the side of the pair that the dihydride unit(s) appear on consistently

• , with both groups showing similar image contrast in STM topography (compare Figure 2i-1,2,3 with Figure 2j-1,2,3 and Supporting Information File 1, Figure S9). Their distinct location with respect to the dimer, however, is easily discerned throughout all analysis types in Figure 2i,j. In Si-tip AFM

• surface. The size of the area shown in (a) is outlined in (e). (c,d) Constant current (I = 50 pA) STM topography probing empty and filled states of the surface (bias voltages indicated in the lower left of each panel). (e) Constant height STM image with a fixed bias and height. (f) Scanning tunnelling

An atomic force microscope integrated with a helium ion microscope for correlative nanoscale characterization

• Santiago H. Andany,
• Gregor Hlawacek,
• Stefan Hummel,
• Charlène Brillard,
• Mustafa Kangül and
• Georg E. Fantner

Beilstein J. Nanotechnol. 2020, 11, 1272–1279, doi:10.3762/bjnano.11.111

• performed without contamination of the sample and environmental changes between processing steps. The practicality of the resulting tool lies in the complementarity of the two techniques. The AFM offers not only true 3D topography maps, something the HIM can only provide in an indirect way, but also allows

• to be navigated onto the region of interest (Figure 2b,c) to perform AFM topography imaging (Figure 2d). PMMA has traditionally been used as a positive resist in electron beam lithography. Helium ion beam lithography has emerged as a powerful technique to achieve even smaller feature size thanks to

• . Figure 3a and Figure 3b show two AFM topography images of PMMA exposed to a dose of 1 × 1013 cm−2 and 3 × 1013 cm−2 30 keV He ions, respectively, as well as the corresponding height profiles of the irradiated PMMA surface. Focused ion beam damage and implantation can hinder the imaging and nanoscale

High permittivity, breakdown strength, and energy storage density of polythiophene-encapsulated BaTiO₃ nanoparticles

• Adnanullah Khan,
• Amir Habib and
• Adeel Afzal

Beilstein J. Nanotechnol. 2020, 11, 1190–1197, doi:10.3762/bjnano.11.103

• the SEM image shown in Figure 4a. PTh, on the other hand, exhibits an inhomogeneous surface morphology with large flakes of polymer randomly distributed on the surface. In case of core–shell BTO-PTh nanoparticles (Figure 5b), the surface topography is very consistent with uniformly distributed sub

• images of the as-prepared BTO nanoparticles (a), BTO-PTh nanoparticles (b), and pristine PTh (c). 3D images showing the surface topography, and 2D images along with surface profiles showing the surface morphology of all samples. Dielectric properties of the as-prepared BTO nanoparticles, pristine PTh

Revealing the local crystallinity of single silicon core–shell nanowires using tip-enhanced Raman spectroscopy

• Marius van den Berg,
• Ardeshir Moeinian,
• Arne Kobald,
• Yu-Ting Chen,
• Anke Horneber,
• Steffen Strehle,
• Alfred J. Meixner and
• Dai Zhang

Beilstein J. Nanotechnol. 2020, 11, 1147–1156, doi:10.3762/bjnano.11.99

• dominant field component lays out-of-plane (parallel to the tip shaft). Figure 4b,c demonstrates that the tip apex can be easily excited, which is a precondition for producing a localized near field at the tip apex. Next, we approached the sample to the tip and recorded the topography (size: 250 × 250 nm2

• , we combined angle-resolved polarization measurements with TERS to investigate the effects of tip–sample interactions on the optical signals. In Figure 6a the topography of a SiNW surface is shown. Along the dashed arrow, 32 spectra were recorded, and eight of them are plotted in Figure 6b. Although

• greatly increased leading to a strong local near field confined at the tip apex. This gives rise to the enhanced sensitivity of tip-enhanced Raman spectroscopy (TERS). TERS combined with scanning probe microscopy (SPM) also allows for the collection of correlated topography and optical images [42][43

Thermophoretic tweezers for single nanoparticle manipulation

• Jošt Stergar and
• Natan Osterman

Beilstein J. Nanotechnol. 2020, 11, 1126–1133, doi:10.3762/bjnano.11.97

• nanodots, so-called plasmonic tweezers [6][7][8] or a fluidic slit with appropriately tailored topography with resulting spatially modulated electrostatic potential [9] can be used to trap nanoparticles, but again a prefabricated nanostructured substrate is needed. A decade ago, the anti-Brownian

Monolayers of MoS₂ on Ag(111) as decoupling layers for organic molecules: resolution of electronic and vibronic states of TCNQ

• Asieh Yousofnejad,
• Gaël Reecht,
• Nils Krane,
• Christian Lotze and
• Katharina J. Franke

Beilstein J. Nanotechnol. 2020, 11, 1062–1071, doi:10.3762/bjnano.11.91

• , although the experimental width prevented us from resolving the individual modes. a) STM topography of MoS2 on Ag(111) recorded at V = 1.2 V, I = 20 pA. Inset: Line profile of a monolayer MoS2 island along the green line. b) Close-up view on the moiré structure. c) Atomically resolved terminating S layer

• (V = 5 mV, I = 1 nA). d) Constant-height dI/dV spectra of MoS2/Ag(111) recorded on a top and on a hollow region of the moiré structure as shown on the inserted STM topography (feedback opened at V = 2.5 V, I = 0.5 nA, Vmod = 10 mV). The inset shows the gap region of MoS2/Ag(111) on a logarithmic

• = 2.5 V, I = 0.5 nA, Vmod = 10 mV (all spectra, except for hollow site on Au(111): Vmod = 5 mV). a) Stick-and-ball model of TCNQ. Gray, blue, and white spheres represent C, N, and H atoms, respectively. b) STM topography of a TCNQ molecular island on MoS2/Ag(111) recorded at V = 1 V, I = 10 pA. c) STM

Measurement of electrostatic tip–sample interactions by time-domain Kelvin probe force microscopy

• Christian Ritz,
• Tino Wagner and
• Andreas Stemmer

Beilstein J. Nanotechnol. 2020, 11, 911–921, doi:10.3762/bjnano.11.76

• –sample bias. This allows for an electrostatic characterization and simultaneously minimizes the electrostatic influence onto the topography measurement. However, a static contribution due to the bias modulation itself remains uncompensated, which can induce topographic height errors. Here, we demonstrate

• results in a continuous measurement of the local surface potential, the capacitance gradient, and the frequency shift induced by surface topography. In contrast to conventional techniques, the detection of the topography-induced frequency shift enables the compensation of all electrostatic influences

• , including the component arising from the bias modulation. This constitutes an important improvement over conventional techniques and paves the way for more reliable and accurate measurements of electrostatics and topography. Keywords: atomic force microscopy (AFM); electrostatic height error; extended

Integrated photonics multi-waveguide devices for optical trapping and Raman spectroscopy: design, fabrication and performance demonstration

• Gyllion B. Loozen,
• Arnica Karuna,
• Mohammad M. R. Fanood,
• Erik Schreuder and
• Jacob Caro

Beilstein J. Nanotechnol. 2020, 11, 829–842, doi:10.3762/bjnano.11.68

• away from the edge. In the next step, a 3 µm thick layer of SiO2 is deposited using LPCVD (Figure 5e). This layer acts as an upper cladding of the excitation waveguides and separates these from the waveguiding layer that follows. For simplicity, we do not show the surface topography resulting after

• are also clearly discernible. The four detection waveguides occupy a maximum space along the sides of the microbath for optimum collection efficiency. The scanning electron microscope (SEM) image in Figure 6c shows the topography of the microbath and the side channels. The DRIE process of these

• layers does not reflect the real situation. The surface topography resulting from the conformal deposition on the etched structures has been omitted in the cross sections. (a) Optical microscope image of a device with 16 excitation and 4 detection waveguides. (b) Magnification of the marked area in (a