Measurement of polarization effects in dual-phase ceria-based oxygen permeation membranes using Kelvin probe force microscopy

• Kerstin Neuhaus,
• Christina Schmidt,
• Liudmila Fischer,
• Wilhelm Albert Meulenberg,
• Ke Ran,
• Joachim Mayer and
• Stefan Baumann

Beilstein J. Nanotechnol. 2021, 12, 1380–1391, doi:10.3762/bjnano.12.102

• were performed in a single-pass experiment. For this kind of measurements, the surface potential and the sample topography are mapped in a single pass in intermittent contact mode with the cantilever vibrating at its resonance frequency (i.e., the cantilever is not in lift mode during this experiment

• ceria materials led to a more positive surface potential in the direct vicinity of the contact area, while a negative voltage led to a more negative surface potential. The surface potential gradient was also shown to be reversible over time as long as the applied voltage was kept in a certain range. The

• electrochemical studies. The surface potential at the direct contact point of the measuring tip can be determined from the KPFM measurement data at different times after the end of polarization. The results usually follow an exponential rule if plotting ΔΦSP versus time. By fitting of the expontential function

Chemical vapor deposition of germanium-rich CrGe_x nanowires

• Vladislav Dřínek,
• Stanislav Tiagulskyi,
• Roman Yatskiv,
• Jan Grym,
• Radek Fajgar,
• Věra Jandová,
• Martin Koštejn and
• Jaroslav Kupčík

Beilstein J. Nanotechnol. 2021, 12, 1365–1371, doi:10.3762/bjnano.12.100

• transfer single NWs onto contact lithographic pads (Supporting Information File 1, Figure S9) to measure their conductivity. The NWs, however, turned out to be fragile and were destroyed when an attempt was made to cut them from the tungsten tip using a focused ion beam (FIB). Therefore, a method to

• directly contact an as-grown single NW was developed. This method allowed us to measure the conductivity between the molybdenum substrate and the point of contact of the tungsten tip with the NW. To limit the contact resistance between the tungsten tip and the NW, the tip was soldered to the NW with a

• with the Ga+ focused ion beam (FIB), gas injection system (GIS), and nanomanipulator OmniProbe 400 (Oxford Instruments) with a tungsten tip. The nanomanipulator enabled a direct contact of single as-grown NWs. The current–voltage (I–V) characteristics were measured using a Keithley 237 source

Cantilever signature of tip detachment during contact resonance AFM

• Devin Kalafut,
• Ryan Wagner,
• Maria Jose Cadena,
• Anil Bajaj and
• Arvind Raman

Beilstein J. Nanotechnol. 2021, 12, 1286–1296, doi:10.3762/bjnano.12.96

• Devin Kalafut Ryan Wagner Maria Jose Cadena Anil Bajaj Arvind Raman School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907, USA 10.3762/bjnano.12.96 Abstract Contact resonance atomic force microscopy, piezoresponse force microscopy, and electrochemical strain microscopy are

• atomic force microscopy modes in which the cantilever is held in contact with the sample at a constant average force while monitoring the cantilever motion under the influence of a small, superimposed vibrational signal. Though these modes depend on permanent contact, there is a lack of detailed analysis

• connect the qualitative and quantitative behavior to experimental features. Keywords: atomic force microscopy (AFM); contact resonance; nonlinear normal mode (NNM); tip–sample detachment; photothermal excitation; Introduction Contact resonance atomic force microscopy (CR-AFM) [1][2], piezoresponse force

Enhancement of the piezoelectric coefficient in PVDF-TrFe/CoFe₂O₄ nanocomposites through DC magnetic poling

• Marco Fortunato,
• Alessio Tamburrano,
• Maria Paola Bracciale,
• Maria Laura Santarelli and
• Maria Sabrina Sarto

Beilstein J. Nanotechnol. 2021, 12, 1262–1270, doi:10.3762/bjnano.12.93

• temperatures. This process, usually referred to as electrical poling, requires the deposition of contact electrodes on the sample surface and the use of high-voltage apparatus. In the present work, in order to overcome these constraints, we have produced, characterized, and studied a polymer nanocomposite

A review on slip boundary conditions at the nanoscale: recent development and applications

• Ruifei Wang,
• Jin Chai,
• Bobo Luo,
• Xiong Liu,
• Jianting Zhang,
• Min Wu,
• Mingdan Wei and
• Zhuanyue Ma

Beilstein J. Nanotechnol. 2021, 12, 1237–1251, doi:10.3762/bjnano.12.91

• affect the boundary slip, and many previous investigations have shown that, from qualitative points of view, the positive slip length monotonically increases with the increase in the contact angle [57][58][59][60][61]. Furthermore, when studying the water flow on smooth surfaces, there is a

• quasiuniversal relationship between the slip length and the static contact angle as follows (see Equation 3 and Figure 2). It has been shown that Equation 3 can be interpreted on the grounds of definite physical principles, according to the microscopic connection between slip length, contact angle, and the

• liquid–solid interaction parameter [62]. However, it should be noted that this model is only applicable to cases of water slippage on smooth surfaces, and there are some deviations for water slippage on rough surfaces [66]. On the other hand, even on very smooth surfaces, the contact angle, surface–water

Two dynamic modes to streamline challenging atomic force microscopy measurements

• Alexei G. Temiryazev,
• Andrey V. Krayev and
• Marina P. Temiryazeva

Beilstein J. Nanotechnol. 2021, 12, 1226–1236, doi:10.3762/bjnano.12.90

• flexible console with a sharp tip at the end. Two main classes of scanning methods can be distinguished, namely contact and dynamic scanning. During contact scanning, the tip is pressed against the surface and the pressing force is controlled by the deflection of the console. A similar way to control the

• interaction of the probe with the sample is used in off-resonance dynamic modes [6]. Although they have various names, depending on the specific manufacturer (PeakForce Tapping, Hybrid Mode, Digital Pulsed Force Mode), a common feature of these methods is that the transition to the contact is carried out

• periodically with a frequency of 1–2 kHz. In addition to the surface profile, contact methods allow one to obtain some information on the mechanical properties of the material, provided that the contact area between the tip and the sample can be modeled with a reasonable degree of accuracy. In the case of the

The effect of cobalt on morphology, structure, and ORR activity of electrospun carbon fibre mats in aqueous alkaline environments

• Markus Gehring,
• Tobias Kutsch,
• Osmane Camara,
• Alexandre Merlen,
• Hermann Tempel,
• Hans Kungl and
• Rüdiger-A. Eichel

Beilstein J. Nanotechnol. 2021, 12, 1173–1186, doi:10.3762/bjnano.12.87

• active sites, that is, triple-phase contact points. These contact points of air, solid catalyst, and liquid electrolyte, need to be high in number or area. This entails a partial wetting of the electrode to ensure accessibility of the sites for gaseous oxygen. From a more industrial perspective

• carbonised at 800 °C, is decreased when the sample is carbonised at 1000 °C. Cobalt is known to instantaneously oxidise upon contact with air even at room temperature forming an oxide layer with a thickness of 0.8 to 1 nm [28]. Considering the low thickness of the layer and the fact that spontaneous

• particle surface is completely reduced and only re-oxidised upon contact with air. From an application point of view, this oxide/hydroxide layer may even prove beneficial, as both cobalt [16] and its oxides [29] have been shown to enhance the ORR in alkaline media. Carbon matrix structure The XRD

Open-loop amplitude-modulation Kelvin probe force microscopy operated in single-pass PeakForce tapping mode

• Gheorghe Stan and
• Pradeep Namboodiri

Beilstein J. Nanotechnol. 2021, 12, 1115–1126, doi:10.3762/bjnano.12.83

• various contributions from the probe geometry and imaged features of the sample. In contrast to this, the currently implemented closed-loop (CL) variants of KPFM, either amplitude-modulation (AM) or frequency-modulation (FM), solely report on their final product in terms of the tip–sample contact

• potential difference. In ambient atmosphere, both CL AM-KPFM and CL FM-KPFM work at their best during the lift part of a two-pass scanning mode to avoid the direct contact with the surface of the sample. In this work, a new OL AM-KPFM mode was implemented in the single-pass scan of the PeakForce Tapping

• (PFT) mode. The topographical and electrical components were combined in a single pass by applying the electrical modulation only in between the PFT tip–sample contacts, when the AFM probe separates from the sample. In this way, any contact and tunneling discharges are avoided and, yet, the location of

Criteria ruling particle agglomeration

• Dieter Vollath

Beilstein J. Nanotechnol. 2021, 12, 1093–1100, doi:10.3762/bjnano.12.81

• known, as a first approximation, the energy of interaction was assumed to be proportional to the number of contact points. As smallest number, for each particle one contact point was assumed. Luo et al. [12] estimate the energy of interaction in the range of approximately h0 = 10 eV (1.6 × 10−18 J

Assessment of the optical and electrical properties of light-emitting diodes containing carbon-based nanostructures and plasmonic nanoparticles: a review

• Keshav Nagpal,
• Erwan Rauwel,
• Frédérique Ducroquet and
• Protima Rauwel

Beilstein J. Nanotechnol. 2021, 12, 1078–1092, doi:10.3762/bjnano.12.80

• : electron transport and injection layers Similar to HTL and HIL, ETL and EIL play very crucial roles in optimizing charge carrier injection in OLED and HyLED. The latter follows an inverted OLED architecture (i.e., the EIL is in contact with the cathode followed by ETL). In order to enhance the OLED

A new method for obtaining model-free viscoelastic material properties from atomic force microscopy experiments using discrete integral transform techniques

• Berkin Uluutku,
• Enrique A. López-Guerra and
• Santiago D. Solares

Beilstein J. Nanotechnol. 2021, 12, 1063–1077, doi:10.3762/bjnano.12.79

• force–distance curve, where the cantilever position above the sample follows a ramp function. In the case of intermittent-contact methods (e.g., tapping-mode AFM), the cantilever tip oscillates nearly sinusoidally, but since tip–sample contact is intermittent, the sample does not experience purely

• geometry correction factor discussed above, . For this calculation Δt is a known experimental parameter, and r is chosen by the researcher. Demonstration with AFM contact mechanics So far, we have demonstrated our method for stress–strain inputs using the generalized Voigt model. However, in AFM

• z-domain. The theoretical retardance is evaluated using Equation 29 (see Supporting Information File 1 for its derivation): A spherical contact, appropriate for an AFM experiment, was simulated using the same material parameters, with a tip radius of 10 nm, which is common in AFM (See also Figure 2

Use of nanosystems to improve the anticancer effects of curcumin

• Andrea M. Araya-Sibaja,
• Norma J. Salazar-López,
• Krissia Wilhelm Romero,
• José R. Vega-Baudrit,
• J. Abraham Domínguez-Avila,
• Carlos A. Velázquez Contreras,
• Ramón E. Robles-Zepeda,
• Mirtha Navarro-Hoyos and
• Gustavo A. González-Aguilar

Beilstein J. Nanotechnol. 2021, 12, 1047–1062, doi:10.3762/bjnano.12.78

• ]. However, both authors only carried out release studies at pH 7.4, so the question of the behavior of LPN at an acid pH remains. Nanoemulsions. Nanoemulsions are composed of an oil phase in a continuous aqueous phase, with average diameters <200 nm [88][89]. The oil and aqueous phases contact each other

An overview of microneedle applications, materials, and fabrication methods

• Zahra Faraji Rad,
• Philip D. Prewett and
• Graham J. Davies

Beilstein J. Nanotechnol. 2021, 12, 1034–1046, doi:10.3762/bjnano.12.77

• parameters determining flow in a microchannel include blood viscosity, contact angle, hydrodynamic diameter, and driving forces such as surface tension. In addition, due to the elastic nature of the skin and its irregular surface, varying from person to person, and with age and position on the body, the

• light. The resist is sprayed or spin coated onto a substrate surface for patterning and is exposed to light (usually ultraviolet) either through a contact mask or using a projection stepper, followed by wet development to form a resist pattern. This technique requires well-established photosensitive

A Au/CuNiCoS₄/p-Si photodiode: electrical and morphological characterization

• Adem Koçyiğit,
• Adem Sarılmaz,
• Teoman Öztürk,
• Faruk Ozel and
• Murat Yıldırım

Beilstein J. Nanotechnol. 2021, 12, 984–994, doi:10.3762/bjnano.12.74

• /H2O (1:10) solution for eliminating the oxide layer and impurities from the surfaces. An ohmic contact with low resistance was made by evaporation of aluminium (Al, 99.999% from Kurt J. Lesker) with a thickness of 150 nm at 5 × 10−6 Torr on the back side of the p-type Si substrate and subsequent

• /CuNiCoS4/p-Si photodiode, and it can be determined from I–V characteristics [28]. Rj contains two components: shunt resistance (Rsh) due to contact of the metal–semiconductor interface and series resistance (Rs) owing to interfacial layers [29]. Rj can be calculated as follows: The Rj–V plots of the Au

Uniform arrays of gold nanoelectrodes with tuneable recess depth

• Elena O. Gordeeva,
• Ilya V. Roslyakov,
• Alexey P. Leontiev,
• Alexey A. Klimenko and
• Kirill S. Napolskii

Beilstein J. Nanotechnol. 2021, 12, 957–964, doi:10.3762/bjnano.12.72

• array and the ability to control the recess depth, and (4) a predictable number of nanoelectrodes in electrical contact with the current collector. In the present study, the first two points are fulfilled by using AAO as a template and Au as the material of the working part of the nanoelectrodes. To

• with electrical contact, Cu was re-deposited on the surface of the Au segments (Figure 3a). The experiment was carried out at Ed = −0.1 V and limited by the electrical charge density, which is equal to the corresponding value in the case of electrodeposition of the first Cu segment. SEM images of the

• AAO surface after Cu re-deposition are shown in Figure 3b,c. The Au nanoelectrodes having electrical contact with the current collector manifest themselves as white dots, indicating that Cu reaches the template surface. Contrary, the black dots correspond to the pores containing recessed Au electrodes

Molecular assemblies on surfaces: towards physical and electronic decoupling of organic molecules

• Sabine Maier and
• Meike Stöhr

Beilstein J. Nanotechnol. 2021, 12, 950–956, doi:10.3762/bjnano.12.71

• . To a lesser extent, metal oxides have also been used, for which defects and charging often pose additional challenges [44][45][46]. On electronically insulating surfaces, non-contact atomic force microscopy (AFM) is the method of choice to study molecular assemblies and individual molecules in real

Self-assembly of Eucalyptus gunnii wax tubules and pure ß-diketone on HOPG and glass

• Miriam Anna Huth,
• Axel Huth and
• Kerstin Koch

Beilstein J. Nanotechnol. 2021, 12, 939–949, doi:10.3762/bjnano.12.70

• amounts of deposited mass. This phenomenon known as “coffee ring effect” is caused by capillary flow of the solvent from the middle of the droplet towards its three-phase (solid–liquid–air) contact line. During evaporation, the molecules are aggregated on the outer edge of the droplet where evaporation is

In situ transport characterization of magnetic states in Nb/Co superconductor/ferromagnet heterostructures

• Olena M. Kapran,
• Roman Morari,
• Taras Golod,
• Evgenii A. Borodianskyi,
• Vladimir Boian,
• Andrei Prepelita,
• Nikolay Klenov,
• Anatoli S. Sidorenko and
• Vladimir M. Krasnov

Beilstein J. Nanotechnol. 2021, 12, 913–923, doi:10.3762/bjnano.12.68

• the whole electrode is measured in a four-probe manner using two separate wires bonded to each contact pad. Results Figure 1d shows Rxx(T) dependencies, normalized by the normal state resistance Rn (T ≥ Tc), for microbridges at S1 (blue) and S2 (red) MLs at H = 0. Resistances are measured with Iac

• landscape for vortices: vortices are pinned to domains and cannot move across them, but can freely move along domain walls [55]. Therefore, we expect that the magnetic state of a ML may influence the FF resistance. Figure 1h shows Rxx(T) for a vertical bridge at the S1 sample measured with the contact

• bridge with widths of a few micrometers. The inset shows the contact configuration for simultaneous measurements of longitudinal and Hall resistances in panels (h) and (i). The orange arrow indicates the orientation of the magnetic field in all experiments. (b) Magnetization curve of an unpatterned Nb(25

Modification of a SERS-active Ag surface to promote adsorption of charged analytes: effect of Cu²⁺ ions

• Bahdan V. Ranishenka,
• Andrei Yu. Panarin,
• Irina A. Chelnokova,
• Sergei N. Terekhov,
• Peter Mojzes and
• Vadim V. Shmanai

Beilstein J. Nanotechnol. 2021, 12, 902–912, doi:10.3762/bjnano.12.67

• support (slide) depending on the time of contact with Ag NPs. The maximum absorption value stabilizes after approximately 12 h with a shift from 412 to 427 nm. We suppose that the redshift of the absorption maximum is due to the plasmon interactions of the closely packed NPs. In order to investigate the

The role of convolutional neural networks in scanning probe microscopy: a review

• Ido Azuri,
• Irit Rosenhek-Goldian,
• Neta Regev-Rudzki,
• Georg Fantner and
• Sidney R. Cohen

Beilstein J. Nanotechnol. 2021, 12, 878–901, doi:10.3762/bjnano.12.66

• conditions for band-excitation piezoresponse force microscopy (PFM) [134]. Band excitation collects a band of frequencies around the contact resonance frequency of the tip–sample system, which is modeled by a simple harmonic oscillator equation. This allows for the determination of several physical

• -topographical SPM technique is the study of ferroelectric switching [135]. This switching is a function of both reading and writing voltages, and can vary with experimental conditions such as time and temperature, and is further complicated by competing processes. The measurement technique was contact KPFM

• , which has an inherently low signal due to damped response of the tip in contact with surface. In this case, the data is not surface mappings, but rather hysteresis loops in graphical format, which were “unfolded” by plotting the voltage response as function of the read voltage and writing voltage step

9.1% efficient zinc oxide/silicon solar cells on a 50 μm thick Si absorber

• Rafal Pietruszka,
• Bartlomiej S. Witkowski,
• Monika Ozga,
• Katarzyna Gwozdz,
• Ewa Placzek-Popko and
• Marek Godlewski

Beilstein J. Nanotechnol. 2021, 12, 766–774, doi:10.3762/bjnano.12.60

• deposited as a low-resistivity ohmic contact via sputtering. To improve the contact parameters, the samples were annealed at 500 °C for 5 min in argon atmosphere via rapid thermal processing. Si/Al substrates were prepared in two different ways, A and B. On the surface of sample A, zinc oxide nanorods

• improved electron collection by band offset engineering. On top of the solar structure, AZO was deposited as a transparent contact [17][18]. Trimethylaluminium (TMA, CAS Number 75-24-1) was used as the Al precursor. In the ALD processes, high-purity nitrogen (purity 99.999%) was used as the carrier gas

• hole of 0.1 cm in diameter was placed on the samples. Then, Al was deposited on top via sputtering. The simple point contact was used on top of the structure. To improve the light collection from full-size ZnO/Si SCs, grid-like contacts should be used. The resulting solar cell structures are shown in

Physical constraints lead to parallel evolution of micro- and nanostructures of animal adhesive pads: a review

• Thies H. Büscher and
• Stanislav N. Gorb

Beilstein J. Nanotechnol. 2021, 12, 725–743, doi:10.3762/bjnano.12.57

• morphology of attachment devices is affected by physical constraints. This resulted in two main types of attachment devices in animals: hairy and smooth. They differ in morphology and ultrastructure but achieve mechanical adaptation to substrates with different roughness and maximise the actual contact area

• influence of different factors, such as substrate roughness and pad stiffness, on contact forces, and review the chemical composition of pad fluids, which is an important component of an adhesive function. Attachment systems are omnipresent in animals. We show parallel evolution of attachment structures on

• contact with a wide range of microscopically rough substrate profiles (Figure 2). Also, due to the low bending stiffness of their terminal plates, can even adapt to substrates with roughness on a sub-nanometre scale [1][3][4][34]. Smooth pads can also maximise their contact areas with a variety of

Electromigration-induced formation of percolating adsorbate islands during condensation from the gaseous phase: a computational study

• Alina V. Dvornichenko,
• Vasyl O. Kharchenko and
• Dmitrii O. Kharchenko

Beilstein J. Nanotechnol. 2021, 12, 694–703, doi:10.3762/bjnano.12.55

• growth of intermetallic compounds between the solder and the metal contact of the integrated circuit (flip-chip technology) [3][4][5][6][7]. The vast majority of research on EM began in the 1970s. Such studies were mostly conducted experimentally. It was shown that the influence of the electric current

• include the formation of surface steps [28][29][30][31], faceting of the surface [32][33][34][35][36][37], elimination of instability of surface morphology caused by stress and wetting of the substrate [38][39][40][41], the evolution of contact irregularities in switches of microelectromechanical systems

Nanogenerator-based self-powered sensors for data collection

• Yicheng Shao,
• Maoliang Shen,
• Yuankai Zhou,
• Xin Cui,
• Lijie Li and
• Yan Zhang

Beilstein J. Nanotechnol. 2021, 12, 680–693, doi:10.3762/bjnano.12.54

• to the safety of vehicle driving and the experience of the driver [5][6][7][8][9][10][11]. The principle of operation of TENGs is the triboelectrification/contact electrification (CE) process [62][63][64]. TENGs have four working modes: the common vertical contact-separation mode, the single

• -electrode mode, the contact-sliding mode, and the freestanding-triboelectric-layer mode [2][65]. TENGs can be made of many different materials with low manufacturing cost, environmental friendliness, and low maintenance cost. TENG-based sensors can collect multidimensional and large-scale data, which are a

• . When the arm is bent, the muscles stretch the sensor to a larger contact area, and a voltage variation is generated by the sensor. An output voltage of about 23 V is generated. When the arm is released, the voltage returns to zero. The peak voltage varies with the bending angle of the elbow, as shown

Nanoporous and nonporous conjugated donor–acceptor polymer semiconductors for photocatalytic hydrogen production

• Zhao-Qi Sheng,
• Yu-Qin Xing,
• Yan Chen,
• Guang Zhang,
• Shi-Yong Liu and
• Long Chen

Beilstein J. Nanotechnol. 2021, 12, 607–623, doi:10.3762/bjnano.12.50

• well as output electrons and build excellent electron-output “tentacles” and therefore increase the HER. Chen et al. [81] reported an ethynyl-bridged FSO–pyrene-based polymer (P66) (Figure 8) to further extend the conjugation. The water contact angle measurements showed that the wettability was