Reduced subthreshold swing in a vertical tunnel FET using a low-work-function live metal strip and a low-k material at the drain

• Kalai Selvi Kanagarajan and
• Dhanalakshmi Krishnan Sadhasivan

Beilstein J. Nanotechnol. 2024, 15, 713–718, doi:10.3762/bjnano.15.59

• to reduce gate oxide leakage are high-k materials. The device’s ability to keep a charge is increased by using high-k materials, which also aids in downsizing. HfO2 is compatible with a silicon substrate and possesses a high dielectric constant (ε ≈ 25), a large bandgap (5.68 eV), band offsets with

• silicon, a low leakage current, and a lattice parameter that is close to that of silicon with a modest lattice misfit (ca. 5%) [11]. In this paper, a published VTFET structure is taken for comparison [12]. A large tunnel area and a thin channel enhance the device metrics [13]. In contrast to the

Elastic modulus of β-Ga₂O₃ nanowires measured by resonance and three-point bending techniques

• Annamarija Trausa,
• Sven Oras,
• Sergei Vlassov,
• Mikk Antsov,
• Tauno Tiirats,
• Andreas Kyritsakis,
• Boris Polyakov and
• Edgars Butanovs

Beilstein J. Nanotechnol. 2024, 15, 704–712, doi:10.3762/bjnano.15.58

• pressure chemical vapour transport in a horizontal quartz tube reactor (18 mm inner diameter) according to the method reported in [2]. The process involved loading a ceramic boat with 0.15 g of Ga2O3 powder (99.99%, Alfa Aesar) at the centre of the quartz tube. Oxidised silicon wafers SiO2/Si (100) coated

• geometry, utilising a 600 W Cu anode (Cu Kα radiation, λ = 1.5406 Å) X-ray tube. In four steps, (100)Si wafers (Semiconductor wafer, Inc.) with 50 nm thermal oxide, were processed to create the patterned silicon substrates with grooves and inverted pyramids. First, the patterns were created in a

• photoresist on the wafer using conventional optical lithography. Next, the SiO2 was selectively removed using a buffered HF solution to replicate the resist pattern in the oxide layer. Then, the silicon was etched at 90 °C in a tetramethylammonium hydroxide (TMAH) solution to create etch pits. Finally, the

Enhancing higher-order modal response in multifrequency atomic force microscopy with a coupled cantilever system

• Wendong Sun,
• Jianqiang Qian,
• Yingzi Li,
• Yanan Chen,
• Zhipeng Dou,
• Rui Lin,
• Peng Cheng,
• Xiaodong Gao,
• Quan Yuan and
• Yifan Hu

Beilstein J. Nanotechnol. 2024, 15, 694–703, doi:10.3762/bjnano.15.57

• parameters Several commercial rectangular multifrequency AFM cantilevers of different sizes from different manufacturers are summarized in [24]. In the ANSYS Workbench finite element simulation, the material used in the simulation is silicon, with a Young's modulus of 166 GPa and a density of 2330 kg/m3. We

• cantilever experimental platform setup used to measure the modal response is shown in Figure 7. The experimental setup consists of a macroscale cantilever (6 × 1 × 0.18 cm, silicon content up to 99.9999%) with left-side clamping and a simple bottom support. A photo is shown in Figure 8. In the experiments

Laser synthesis of nanoparticles in organic solvents – products, reactions, and perspectives

• Theo Fromme,
• Sven Reichenberger,
• Katharine M. Tibbetts and
• Stephan Barcikowski

Beilstein J. Nanotechnol. 2024, 15, 638–663, doi:10.3762/bjnano.15.54

• femtosecond and picosecond irradiation of solvents including toluene, hexane, acetone, and acetonitrile [117][162][163]. Nanodiamonds have been obtained through femtosecond irradiation of ethanol [164][165]. Fluorescent carbon dots were also observed as a by-product when synthesizing 1-octene-capped silicon

AFM-IR investigation of thin PECVD SiO_x films on a polypropylene substrate in the surface-sensitive mode

• Hendrik Müller,
• Hartmut Stadler,
• Teresa de los Arcos,
• Adrian Keller and
• Guido Grundmeier

Beilstein J. Nanotechnol. 2024, 15, 603–611, doi:10.3762/bjnano.15.51

• /bjnano.15.51 Abstract Thin silicon oxide films deposited on a polypropylene substrate by plasma-enhanced chemical vapor deposition were investigated using atomic force microscopy-based infrared (AFM-IR) nanospectroscopy in contact and surface-sensitive mode. The focus of this work is the comparison of

• signal of the substrate material could be significantly reduced. Even layers that are so thin that they could hardly be measured in the contact mode can be analyzed with the surface-sensitive mode. Keywords: AFM-IR; polypropylene; surface-sensitive mode; silicon oxide; thin films; XPS; Introduction

• sample excitation). However, it is much more flexible in the choice of the drive and detection frequencies, as only the mixing frequency needs to match a system resonance and not the individual frequencies themselves. Here, we use AFM-IR in the surface-sensitive mode to investigate thin silicon oxide

Stiffness calibration of qPlus sensors at low temperature through thermal noise measurements

• Laurent Nony,
• Sylvain Clair,
• Daniel Uehli,
• Aitziber Herrero,
• Jean-Marc Themlin,
• Andrea Campos,
• Franck Para,
• Alessandro Pioda and
• Christian Loppacher

Beilstein J. Nanotechnol. 2024, 15, 580–602, doi:10.3762/bjnano.15.50

• little precision. An accurate stiffness calibration is therefore mandatory if accurate force measurements are targeted. In nc-AFM, the probe may either be a silicon cantilever, a quartz tuning fork (QTF), or a length extensional resonator (LER). When used in ultrahigh vacuum (UHV) and at low temperature

• the framework focuses on a particular kind of sensor, it may be adapted to any high-k, high-Q nc-AFM probe used under similar conditions, such as silicon cantilevers and LERs. Keywords: low temperature; non-contact atomic force microscopy; qPlus sensors; quartz tuning fork; stiffness calibration

• and at room temperature, nc-AFM experiments are mostly carried out with silicon cantilevers, similar to those used during AFM experiments in air or in liquid. Their stiffness rarely exceeds 100 N/m. In UHV and at low temperature, the use of cantilevers is more tedious because of the required in situ

Fabrication of nanocrystal forms of ᴅ-cycloserine and their application for transdermal and enteric drug delivery systems

• Hsuan-Ang Tsai,
• Tsai-Miao Shih,
• Theodore Tsai,
• Jhe-Wei Hu,
• Yi-An Lai,
• Jui-Fu Hsiao and
• Guochuan Emil Tsai

Beilstein J. Nanotechnol. 2024, 15, 465–474, doi:10.3762/bjnano.15.42

• other hand, only a few research articles reported DCS formulations for parenteral administration [18][19]. Nanocarriers offer great advantages to many technological fields. For example, polytetrafluoroethylene (PTFE) with silicon carbide nanocrystals can be applied as a photostabilizer or as a UV light

Sidewall angle tuning in focused electron beam-induced processing

• Sangeetha Hari,
• Willem F. van Dorp,
• Johannes J. L. Mulders,
• Piet H. F. Trompenaars,
• Pieter Kruit and
• Cornelis W. Hagen

Beilstein J. Nanotechnol. 2024, 15, 447–456, doi:10.3762/bjnano.15.40

• ) and from the BSE (SE2) [6][7][8]. An example of a line deposited from a carbon precursor on a silicon substrate, coated with a 20 nm Au–Pd layer and a 5 nm Ti adhesion layer, is shown in Figure 1a, clearly showing the broad (black) tails on both sides of the line. The cross section of the line, made

• , section S1 for more details on the simulation). Sidewall slope evolution under FEBIE To experimentally study the modification of the sidewalls of a FEBID structure, carbon structures were first deposited on a silicon substrate with a 20 nm gold–palladium layer and a 5 nm titanium adhesion layer. The

• MeCpPtMe3. Then the sample was tilted by 52° and milled with a gallium FIB. The cross-sectional profile was imaged at low energy (2 keV) with the SE detector. SE image of a deposited FEBID carbon line, top view (a) and FIB cross section (b). The line was deposited from a dodecane precursor on a silicon

Heat-induced morphological changes in silver nanowires deposited on a patterned silicon substrate

• Elyad Damerchi,
• Sven Oras,
• Edgars Butanovs,
• Allar Liivlaid,
• Mikk Antsov,
• Boris Polyakov,
• Annamarija Trausa,
• Veronika Zadin,
• Andreas Kyritsakis,
• Loïc Vidal,
• Karine Mougin,
• Siim Pikker and
• Sergei Vlassov

Beilstein J. Nanotechnol. 2024, 15, 435–446, doi:10.3762/bjnano.15.39

• specially patterned silicon wafers so that some NWs were partially suspended over the holes in the substrate. Then, we performed a series of heat-treatment experiments and found that adhered and suspended parts of NWs behave differently under the heat treatment. Moreover, depending on the heat-treatment

• for various novel applications where arrays of metal nanostructures are used, such as surface-enhanced Raman spectroscopy substrates [36][37][38]. In this work, we deposited Ag NWs on specially patterned silicon (Si) substrates, so large fractions of NWs are partially suspended over the holes. Samples

• silicon substrates with square holes were prepared from (100) silicon wafers (Semiconductor Wafer, Inc.) with 50 nm thermal oxide in four steps as follows: 1) conventional optical lithography process to produce the desired pattern in a photoresist on the wafer; 2) selective removal of SiO2 using buffered

Investigating ripple pattern formation and damage profiles in Si and Ge induced by 100 keV Ar⁺ ion beam: a comparative study

• Indra Sulania,
• Harpreet Sondhi,
• Tanuj Kumar,
• Sunil Ojha,
• G R Umapathy,
• Ambuj Mishra,
• Ambuj Tripathi,
• Richa Krishna,
• Devesh Kumar Avasthi and
• Yogendra Kumar Mishra

Beilstein J. Nanotechnol. 2024, 15, 367–375, doi:10.3762/bjnano.15.33

• understood. Despite controlled fabrication of patterns has been achieved, details that influence the process of self-assembly still remain open. Ion beam sputtering is an important method for inducing topographical changes in specific materials. For silicon, self-organized dots, ripples, and cones have been

• or range of damage profiles. Single-crystal materials (e.g. silicon and germanium) are composed of ordered arrays of atoms. If an ion beam is aligned to the atomic planes, most of the ions pass through the interplanar space and penetrate deep into the crystal. This can be used in channelling studies

Modulated critical currents of spin-transfer torque-induced resistance changes in NiCu/Cu multilayered nanowires

• Mengqi Fu,
• Roman Hartmann,
• Julian Braun,
• Sergej Andreev,
• Torsten Pietsch and
• Elke Scheer

Beilstein J. Nanotechnol. 2024, 15, 360–366, doi:10.3762/bjnano.15.32

• Discussion The AAO template was fabricated by directly anodizing a ca. 1 µm thick aluminum (Al) film on a silicon (Si) substrate covered with 200 nm SiO2 and patterned Ti/Au (5/50 nm) bottom electrodes. It has pores with a diameter of around 35 nm, an interpore distance of around 50 nm, and a height of

Determining by Raman spectroscopy the average thickness and N-layer-specific surface coverages of MoS₂ thin films with domains much smaller than the laser spot size

• Felipe Wasem Klein,
• Jean-Roch Huntzinger,
• Vincent Astié,
• Damien Voiry,
• Romain Parret,
• Houssine Makhlouf,
• Sandrine Juillaguet,
• Jean-Manuel Decams,
• Sylvie Contreras,
• Périne Landois,
• Ahmed-Azmi Zahab,
• Jean-Louis Sauvajol and
• Matthieu Paillet

Beilstein J. Nanotechnol. 2024, 15, 279–296, doi:10.3762/bjnano.15.26

• ) on the precise evaluation of the integrated intensities of the phonon modes of MoS2, namely A(A1g) and A(E12g), with respect to the integrated intensity of the 521 cm−1 mode from a bare area of the oxidized silicon substrate, A0(Si), used as an intensity reference [31], or from the silicon substrate

• -Stokes intensity ratio of A1g phonon modes (similar results are obtained using E12g) and that of silicon from the Stokes/anti-Stokes intensity ratio of the 521 cm−1 Si mode (see [42] for method details). While the silicon temperature is quasi-insensitive to Pλ, the temperature of MoS2 flakes changes

• ratio, it is of great practical advantage to use the same silicon (the silicon below the oxide, which is Si(100) in the present work) in the measurement of A2D(Si) and A0(Si). A necessary precaution is that the Si(100) substrate orientation has to be kept the same for both measurements. Another

Design, fabrication, and characterization of kinetic-inductive force sensors for scanning probe applications

• August K. Roos,
• Ermes Scarano,
• Elisabet K. Arvidsson,
• Erik Holmgren and
• David B. Haviland

Beilstein J. Nanotechnol. 2024, 15, 242–255, doi:10.3762/bjnano.15.23

• nitride (Nb-Ti-N) [20][25], or granular aluminum (grAl) [26][27], wolfram (W) [28], and silicon doped with boron (Si:B) [29]. Results and Discussion Figure 1 gives an overview of our fabricated sensor, showing the main components. The cantilever is a 600 nm thick Si-N triangular plate released from a much

• thicker silicon (Si) support, as shown in Figure 1a and Figure 1g. Figure 1a shows the microwave resonant circuit with its interdigital capacitor in series with the nanowire inductor. The meandering nanowire is placed at the base of the cantilever as shown in Figure 1c, in the area of largest strain

• of roughly 6 μm/min. This results in all the samples on the wafer being supported by a thin layer of silicon close to the top side. (h) Release and cantilever under-etch. A simple and fast method of release uses an isotropic dry-etch that completes the chip’s release from the wafer and removes the

Quantitative wear evaluation of tips based on sharp structures

• Ke Xu and
• Houwen Leng

Beilstein J. Nanotechnol. 2024, 15, 230–241, doi:10.3762/bjnano.15.22

• analyze the shape of the tip, we use a probe to scan a TipCheck calibration sample and characterize its morphology. The TipCheck sample, provided by BudgetSensors, consists of a silicon chip sample with a wear-resistant thin film coating. The thin film coating exhibits granular and sharp nanostructures

Ion beam processing of DNA origami nanostructures

• Leo Sala,
• Agnes Zerolová,
• Violaine Vizcaino,
• Alain Mery,
• Alicja Domaracka,
• Hermann Rothard,
• Philippe Boduch,
• Dominik Pinkas and
• Jaroslav Kocišek

Beilstein J. Nanotechnol. 2024, 15, 207–214, doi:10.3762/bjnano.15.20

• . Preparation of dry samples and AFM imaging Silicon wafers were cut into ∼7 × 7 mm2 chips and were then plasma-cleaned in air using a Roplass RPS40+ plasma cleaner, which generates a thin layer of plasma by diffuse coplanar surface barrier discharge [35]. The Si surface is exposed to the thin plasma layer for

CdSe/ZnS quantum dots as a booster in the active layer of distributed ternary organic photovoltaics

• Gabriela Lewińska,
• Piotr Jeleń,
• Zofia Kucia,
• Maciej Sitarz,
• Łukasz Walczak,
• Bartłomiej Szafraniak,
• Jerzy Sanetra and
• Konstanty W. Marszalek

Beilstein J. Nanotechnol. 2024, 15, 144–156, doi:10.3762/bjnano.15.14

• are used in opto- and nanoelectronics. QDs establish a class of materials transitional between subatomic and mass types of matter. The classification of QDs according to the core material is divided into cadmium [7][8], silver [9][10], indium [9], carbon [11][12], and silicon [13][14]. Numerous

• carried out for three incidence angles (65°, 70°, and 75°). A Bruker atomic force microscope (AFM) MULTIMODE 8 was used in the measurements in the ScanAsyst in Air mode, using silicon nitride probes (with a nominal tip radius of 2 nm and a spring constant equal to 0.4 N/m). The substrate was

• monocrystalline silicon. A WITec Alpha 300 M+ spectrometer with a 488 nm laser, 600 groove grating, and a 100× ZEISS objective was used for Raman measurements. The samples were deposited on a glass substrate. Ultraviolet photoelectron spectroscopy (UPS) was conducted in an ultrahigh-vacuum chamber with a base

Influence of conductive carbon and MnCo₂O₄ on morphological and electrical properties of hydrogels for electrochemical energy conversion

• Sylwia Pawłowska,
• Karolina Cysewska,
• Yasamin Ziai,
• Jakub Karczewski,
• Piotr Jasiński and
• Sebastian Molin

Beilstein J. Nanotechnol. 2024, 15, 57–70, doi:10.3762/bjnano.15.6

• an accelerating voltage of 10 kV. Before imaging, the hydrogel samples were freeze-dried and coated with a 10 nm gold layer. The chemical composition of the hydrogel was analysed with a Thermo Fisher Scientific silicon drift detector energy-dispersive X-ray spectroscope. For characterisation of the

Measurements of dichroic bow-tie antenna arrays with integrated cold-electron bolometers using YBCO oscillators

• Leonid S. Revin,
• Dmitry A. Pimanov,
• Alexander V. Chiginev,
• Anton V. Blagodatkin,
• Viktor O. Zbrozhek,
• Andrey V. Samartsev,
• Anastasia N. Orlova,
• Dmitry V. Masterov,
• Alexey E. Parafin,
• Victoria Yu. Safonova,
• Anna V. Gordeeva,
• Andrey L. Pankratov,
• Leonid S. Kuzmin,
• Anatolie S. Sidorenko,
• Silvia Masi and
• Paolo de Bernardis

Beilstein J. Nanotechnol. 2024, 15, 26–36, doi:10.3762/bjnano.15.3

• We consider properties of dichroic antenna arrays on a silicon substrate with integrated cold-electron bolometers to detect radiation at frequencies of 210 and 240 GHz. This frequency range is widely used in cosmic microwave background experiments in space, balloon, and ground-based missions such as

• TES bolometers. The low- and mid-frequency arrays consist of dual- and triple-frequency detectors combined with sinusoidal antennas and silicon lenses. The high-frequency array consists of single- and dual-frequency detectors with orthomodal transducers and silicon horns. This array is aimed at 195

• antennas for frequencies of 210 and 240 GHz with cold-electron bolometers, described in the present paper, is proposed to be suitable for such applications. Two arrays placed on a single silicon chip with 7 mm × 7 mm size can independently detect radiation at two frequencies. Here, in the design of

TEM sample preparation of lithographically patterned permalloy nanostructures on silicon nitride membranes

• Joshua Williams,
• Michael I. Faley,
• Joseph Vimal Vas,
• Peng-Han Lu and
• Rafal E. Dunin-Borkowski

Beilstein J. Nanotechnol. 2024, 15, 1–12, doi:10.3762/bjnano.15.1

• Abstract We have prepared ferromagnetic nanostructures intended for the investigation of high-frequency magnetization dynamics in permalloy (Py) nanodisks using Lorentz transmission electron microscopy (LTEM) and electron holography. Py nanodisks were fabricated on thin silicon nitride (SiN) membranes

• layer on the resist, creating fences on the edge of the structure and contaminating the silicon nitride membrane. A possible solution is replacing IBE with reactive ion etching (RIE). Using RIE, there would be less redeposition since the reaction between gas and etched metal will form a gaseous compound

Determination of the radii of coated and uncoated silicon AFM sharp tips using a height calibration standard grating and a nonlinear regression function

• Perawat Boonpuek and
• Jonathan R. Felts

Beilstein J. Nanotechnol. 2023, 14, 1200–1207, doi:10.3762/bjnano.14.99

• measured using a tip characterizer and tip qualification or standard calibration grating. In one of those studies, the tip geometry was determined by using a well-known sharp-edged silicon structure, which included height patterns with a certified pitch on a nanostructure plate [10]. Three types of AFM

• tips (silicon nitride, silicon, and high-aspect-ratio tips) were scanned over the calibration pattern. Simultaneously, the AFM measurement signal showed the tip path profile as the real geometry of a fabricated microstructure. The tip radius was obtained from the curvature radius of the curve profile

• silicon tip (HQ:CSC17/No Al, nominal radius < 8 nm for regular force contact AFM; Figure 1c), all supplied by MikroMasch. The full cone angle for all tips is 40° as given by MikroMasch [9]. The tip end is a hemisphere with specific radius. For the coated tips, the tip radius includes the coating material

Dual-heterodyne Kelvin probe force microscopy

• Benjamin Grévin,
• Fatima Husainy,
• Dmitry Aldakov and
• Cyril Aumaître

Beilstein J. Nanotechnol. 2023, 14, 1068–1084, doi:10.3762/bjnano.14.88

• ), driven by a Mimea scanning probe microscope (SPM) controller (SPECS-Nanonis). Topographic imaging is performed in FM mode (FM-AFM) in the attractive regime, with negative frequency shifts of a few Hz and vibration amplitudes of a few tens of nm. All experiments were performed with Pt/Ir coated silicon

Spatial mapping of photovoltage and light-induced displacement of on-chip coupled piezo/photodiodes by Kelvin probe force microscopy under modulated illumination

• Zeinab Eftekhari,
• Nasim Rezaei,
• Hidde Stokkel,
• Jian-Yao Zheng,
• Andrea Cerreta,
• Ilka Hermes,
• Minh Nguyen,
• Guus Rijnders and
• Rebecca Saive

Beilstein J. Nanotechnol. 2023, 14, 1059–1067, doi:10.3762/bjnano.14.87

• In this work, a silicon photodiode integrated with a piezoelectric membrane is studied by Kelvin probe force microscopy (KPFM) under modulated illumination. Time-dependent KPFM enables simultaneous quantification of the surface photovoltage generated by the photodiode as well as the resulting

• zirconate titanate (PZT), was integrated onto a silicon photodiode. The PZT layer was sandwiched between two lanthanum nickelate (LNO) electrodes and ultimately the backside of the silicon substate was etched to enhance the motion of the membrane. More detailed information on the fabrication and cross

• -sectional scanning electron microscopy images can be found in [32]. The top view of the piezo/photodiode device is given in Figure 1a, where the inset represents the cross section of the device stack. Owing to the integration of PZT with silicon processing and operation at low voltages, this device can be

Isolation of cubic Si₃P₄ in the form of nanocrystals

• Polina K. Nikiforova,
• Sergei S. Bubenov,
• Vadim B. Platonov,
• Andrey S. Kumskov,
• Nikolay N. Kononov,
• Tatyana A. Kuznetsova and
• Sergey G. Dorofeev

Beilstein J. Nanotechnol. 2023, 14, 971–979, doi:10.3762/bjnano.14.80

• Centre «Crystallography and Photonics», Russian Academy of Sciences, 59 Leninskiy prospekt, Moscow, Russia Prokhorov General Physics Institute, Russian Academy of Sciences, 38 Vavilov Str., Moscow, Russia 10.3762/bjnano.14.80 Abstract This article describes an approach for synthesizing silicon phosphide

• nanoparticles with a defective zinc blende structure under mild conditions through thermal annealing of hydrogenated silicon nanoparticles with red phosphorus. The synthesized Si3P4 nanoparticles were analyzed using FTIR, XRD, electron diffraction, EDX, TEM, Raman spectroscopy, X-ray fluorescence spectrometry

• precursor for diffusion doping of wafers and as anode material for Li-ion batteries. A similar method with a hydrogenation step offers the possibility to obtain other compounds, such as silicon selenides, arsenides, and sulfides. Keywords: ampoule annealing; defective zinc blende structure; DFT

Low temperature atomic layer deposition of cobalt using dicobalt hexacarbonyl-1-heptyne as precursor

• Mathias Franz,
• Mahnaz Safian Jouzdani,
• Lysann Kaßner,
• Marcus Daniel,
• Frank Stahr and
• Stefan E. Schulz

Beilstein J. Nanotechnol. 2023, 14, 951–963, doi:10.3762/bjnano.14.78

• crystal 200 mm silicon (100) wafers with a pre-coated thermal SiO2 film of 100 nm thickness. As precursor for all depositions dicobalt hexacarbonyl-1-heptyne [Co2(CO)6HC≡CC5H11] was used. The precursor was synthesised according to Georgi et al. [23] and filled to a common 200 mL stainless steel bubbler

Upscaling the urea method synthesis of CoAl layered double hydroxides

• Camilo Jaramillo-Hernández,
• Víctor Oestreicher,
• Martín Mizrahi and
• Gonzalo Abellán

Beilstein J. Nanotechnol. 2023, 14, 927–938, doi:10.3762/bjnano.14.76

• electron microscopy (SEM) Scanning electron microscopy data was acquired using a Hitachi S-4800, with a beam energy of 5 keV. The samples on silicon wafers were directly investigated without any surface coating. Energy dispersive X-ray (EDS) spectroscopy studies were performed on a Hitachi S-4800

• microscope at an accelerating voltage of 20 kV. Atomic force microscopy (AFM) AFM was carried out with a Bruker Dimension Icon microscope in scan-assist-mode. A Bruker Scanasyst-Air silicon tip with a diameter of around 10 nm was used to obtain images with a resolution of 512 × 512 or 1024 × 1024 pixels. The