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

• have been developed to describe specific kinds of relaxation behavior in the material. For example, in some cases, the analysis involves an assumption regarding discrete characteristic relaxation timescales in the material, which are represented using spring–dashpot models [20][24], while in other

Revealing the formation mechanism and band gap tuning of Sb₂S₃ nanoparticles

• Maximilian Joschko,
• Franck Yvan Fotue Wafo,
• Christina Malsi,
• Danilo Kisić,
• Ivana Validžić and
• Christina Graf

Beilstein J. Nanotechnol. 2021, 12, 1021–1033, doi:10.3762/bjnano.12.76

• explained by different preparation conditions [49]. Different formation mechanisms can lead to differences in bond lengths and angles in an amorphous material, and therefore to a different mobility gap [46]. Hence, a decreasing mobility gap suggests that an electronic relaxation process occurs after a

• range of 2.18 ± 0.03 to 2.01 ± 0.03 eV. In contrast, the optical band gap of the crystalline particles decreased to a value of 1.71 ± 0.03 eV and did not change any further. The reduction of the mobility gap of the amorphous states of the particles was likely due to an electronic relaxation effect with

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

• assemblies [23][28][60][61]. Similarly, the lack of electronic states around the Fermi level in a superconductor was used to preserve electronic properties in adsorbed molecules. For example, the spin relaxation in magnetic molecules was suppressed on a superconducting surface, which then resulted in a

Prediction of Co and Ru nanocluster morphology on 2D MoS₂ from interaction energies

• Cara-Lena Nies and
• Michael Nolan

Beilstein J. Nanotechnol. 2021, 12, 704–724, doi:10.3762/bjnano.12.56

• multiplied by n, the number of atoms in adsorbed Con or Run. 2. Binding energy with reference to a free Con or Run cluster: where Emetal_cluster is the single point energy of the Con or Run nanocluster structure in vacuum. Emonolayer* is the single point energy of the monolayer after relaxation. We chose to

• configuration of Co2 adsorbed at site hollow, during relaxation one Co atom migrated to site atop_S, making this a non-equivalent adsorption at separated sites atop_S - hollow, as shown in Figure 3F. This explains the less favourable binding energy of −4.92 eV compared to −5.73 eV at equivalent neighbouring

• an initial configuration of neighbouring Ru at site hollow (Figure 4C), are caused by the attempted incorporation of one Ru atom into the S layer during relaxation. This has also caused an S atom adjacent to Ru to move out of the surface and bond to both Ru atoms from above, forming a triangular Ru2S

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

• ) converts the energy of blood flow into electrical energy in the heart, which is used to detect changes in EP in real time [29]. The SEPS was implanted in the left atrium of a Yorkshire pig. Figure 3c shows the output voltages during cardiac contraction and relaxation. The changes in the output voltage

Surface-enhanced Raman scattering of water in aqueous dispersions of silver nanoparticles

• Paulina Filipczak,
• Krzysztof Hałagan,
• Jacek Ulański and
• Marcin Kozanecki

Beilstein J. Nanotechnol. 2021, 12, 497–506, doi:10.3762/bjnano.12.40

• enhanced by the mobility decrease in the nearest vicinity of the metal nanoparticle and by the increase of the rotational relaxation time and residence time of water molecules surrounding the ion wall in a charged monolayer-protected Au nanoparticle [39]. Assuming that the observed Raman enhancement is

Reconstruction of a 2D layer of KBr on Ir(111) and electromechanical alteration by graphene

• Zhao Liu,
• Antoine Hinaut,
• Stefan Peeters,
• Sebastian Scherb,
• Ernst Meyer,
• Maria Clelia Righi and
• Thilo Glatzel

Beilstein J. Nanotechnol. 2021, 12, 432–439, doi:10.3762/bjnano.12.35

• a new surface structure, different from the one on other metal substrates such as Cu(111) [42]. Now, the question arises if this structure is a moiré lattice (lateral relaxation) induced by an alternating strength of interaction forces or a new reconstruction of the KBr layer. To search for this

Spontaneous shape transition of Mn_xGe_1−x islands to long nanowires

• S. Javad Rezvani,
• Luc Favre,
• Gabriele Giuli,
• Yiming Wubulikasimu,
• Isabelle Berbezier,
• Augusto Marcelli,
• Luca Boarino and
• Nicola Pinto

Beilstein J. Nanotechnol. 2021, 12, 366–374, doi:10.3762/bjnano.12.30

• relieve the epitaxial strain between the 2D Mn layer and the substrate occurs (significantly increasing the critical thickness for crystallographic defects nucleation). Second, there is the spontaneous elongation of 3D islands also induced by strain relaxation, which is the driving force leading to the

• controlled by the interplay between contributions from the relevant surface and interface energies, Es, and the energy variations due to the elastic relaxation, Er [34]. The sum of these two energy terms, E = Es + Er, represents the total increment of the island energy. In this scenario, the transition from

• larger islands to elongated wires occurs due to the elastic relaxation of the strained islands. Assuming, for simplicity, a rectangular island [34] for which s, t, and h are the width, length, and height, respectively, the minimization of the island energy requires the fulfilment of the condition s = t

Nickel nanoparticle-decorated reduced graphene oxide/WO₃ nanocomposite – a promising candidate for gas sensing

• Ilka Simon,
• Alexandr Savitsky,
• Rolf Mülhaupt,
• Vladimir Pankov and
• Christoph Janiak

Beilstein J. Nanotechnol. 2021, 12, 343–353, doi:10.3762/bjnano.12.28

• flanges with air purge pipes. Therefore, it was practically impossible to measure the relaxation time in a heated cell. Even at room temperature, at best, the measurement procedure will be incorrect, since the possible recovery time is comparable to the time of manipulations with the cell components

Out-of-plane surface patterning by subsurface processing of polymer substrates with focused ion beams

• Serguei Chiriaev,
• Luciana Tavares,
• Vadzim Adashkevich,
• Arkadiusz J. Goszczak and
• Horst-Günter Rubahn

Beilstein J. Nanotechnol. 2020, 11, 1693–1703, doi:10.3762/bjnano.11.151

• 1.32 to 2.97 MPa [28], provides a long-range strain relaxation when compared to a short-range strain relaxation in non-elastic polymers, such as PMMA and PC. Therefore, instead of directly projecting the initially flat surface to another depth position, the irradiation-induced strain warps the pristine

• level above which changes in the structural reconstruction processes are observed. This leads to the transition from a compacting to an expanding phase. We emphasize that such a transition is favorable from a thermodynamic point of view because the volume expansion provides relaxation of the tensile

• strain specifically at the compacted regions. Therefore, it results in the reduction of the strain energy accumulated in the system. The energy minimization provides a thermodynamic force for the strain relaxation. In addition to this, the ion irradiation is needed to break atomic bonds and to lower the

Amorphized length and variability in phase-change memory line cells

• Nafisa Noor,
• Sadid Muneer,
• Raihan Sayeed Khan,
• Anna Gorbenko and
• Helena Silva

Beilstein J. Nanotechnol. 2020, 11, 1644–1654, doi:10.3762/bjnano.11.147

• parameter, is difficult to be extracted. Since the threshold voltage, Vthreshold(t), drifts upward in time [20], an effective threshold field, Ethreshold(t), is also expected to drift similarly, while the amorphized length, Lamorphized, is expected to remain the same over time, despite structural relaxation

Selective detection of complex gas mixtures using point contacts: concept, method and tools

• Alexander P. Pospelov,
• Victor I. Belan,
• Dmytro O. Harbuz,
• Volodymyr L. Vakula,
• Lyudmila V. Kamarchuk,
• Yuliya V. Volkova and
• Gennadii V. Kamarchuk

Beilstein J. Nanotechnol. 2020, 11, 1631–1643, doi:10.3762/bjnano.11.146

• breath components interact with the sensing elements of the point-contact sensor matrix. When the exposure is over, the sensor cell is removed from the mouth and the relaxation of the sensor in the ambient atmospheric environment begins. The relaxation time depends on the composition of the breath and

• usually is in the range of 1–3 min. Thus, the whole process of registering the breath profile occurs in real time. After the relaxation, the sensor is ready for the next measurement. To increase the reproducibility and reliability of the obtained results, we made three consecutive measurements for each

• the sensing element. A condensate film formed on the gas-sensing surface switches on the autonomous power supply of the sensing element, enabling the observation and measurement of the dynamics of resistance variation during the exposure and relaxation periods. This is due to the fact that, in the

Detecting stable adsorbates of (1S)-camphor on Cu(111) with Bayesian optimization

• Jari Järvi,
• Patrick Rinke and
• Milica Todorović

Beilstein J. Nanotechnol. 2020, 11, 1577–1589, doi:10.3762/bjnano.11.140

• construct the surrogate model of the PES by sampling the adsorption energies with DFT (I). We then identify the stable structures by extracting the local minima of the PES (II) and verify them with full structural relaxation with DFT (III). We analyze the relaxed structures (IV) regarding their stability

• Results section, after we have introduced the camphor/Cu(111) system in more detail. Structural relaxation and analysis We verify the identified structures against a full DFT structure relaxation. In this, we remove the building block approximation and allow unrestricted motion of all atoms according to

• the interatomic forces in DFT. We then quantify and analyze the structural changes in the relaxation with respect to the atomic coordinates and the energy change () for each structure. To validate the building block approximation, we evaluate the changes in the internal geometry of the building blocks

Optically and electrically driven nanoantennas

• Monika Fleischer,
• Dai Zhang and
• Alfred J. Meixner

Beilstein J. Nanotechnol. 2020, 11, 1542–1545, doi:10.3762/bjnano.11.136

• photons as a consequence of radiative plasmon relaxation [34][35][36]. The relaxation depends on how the gap modes couple and can hence be controlled by the design of the antenna. The combination of an electrically driven antenna with optical excitation is a very promising but not yet well explored

Adsorption and self-assembly of porphyrins on ultrathin CoO films on Ir(100)

• Feifei Xiang,
• Tobias Schmitt,
• Marco Raschmann and
• M. Alexander Schneider

Beilstein J. Nanotechnol. 2020, 11, 1516–1524, doi:10.3762/bjnano.11.134

• orientation. The slabs were separated by approximately 12 Å of vacuum (measured from the topmost atom of the adsorbed molecule), resulting in a third cell dimension of 23 Å and 25 Å, respectively. For structural relaxation all molecular atoms were allowed to relax. Only in the case of 1, the central Co atom

• ) with a relaxation based on the configuration of 1 with the central Co atom replaced by two H atoms and two cyano groups attached to the phenyl rings of 1, that is, a 2H-dicyanophenylporphyrin. Upon relaxation the macrocycle flattened and the cyanophenyl rings reduced their tilts from the almost

• orthogonal configuration towards a 45° tilting angle. This indicated an energy gain upon flattening of the molecule and allows for an interaction between the cyano group and the substrate. Consequently, we tested the relaxation of 2 in several attempts starting with configurations where the phenyl rings were

A wideband cryogenic microwave low-noise amplifier

• Boris I. Ivanov,
• Dmitri I. Volkhin,
• Ilya L. Novikov,
• Dmitri K. Pitsun,
• Dmitri O. Moskalev,
• Ilya A. Rodionov,
• Evgeni Il’ichev and
• Aleksey G. Vostretsov

Beilstein J. Nanotechnol. 2020, 11, 1484–1491, doi:10.3762/bjnano.11.131

• from a cLNA is introduced to the sample, which might be crucial for the main qubit parameters, especially for the relaxation time T1 and coherence time T2. Therefore, cryogenic microwave isolators are used between the sample and the cLNA. Most of the modern cryogenic amplifiers operate at temperatures

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

• evolution of a sharp line (one example marked by an arrow in Figure 2d), which suggests a relaxation of the front tip apex in agreement with earlier observations in organic [33][34] or inorganic [35][36] systems. For the smallest tip–sample separation, two short elongated dark segments (see markers in

On the frequency dependence of viscoelastic material characterization with intermittent-contact dynamic atomic force microscopy: avoiding mischaracterization across large frequency ranges

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

Beilstein J. Nanotechnol. 2020, 11, 1409–1418, doi:10.3762/bjnano.11.125

• not fully recover its original geometry upon retraction of the probe [15][16][17][18]. The probe does not recover all the work it originally imparted to the material, and the material remains deformed and gradually approaches its original geometry according to its characteristic relaxation timescales

• on the standard-linear-solid model and on power-law rheological models, which can be thought of as infinite collections of spring–damper combinations that form a continuous relaxation spectrum governed by a power-law. In both approaches, from the constants of the model one can easily obtain the

• of intricacies in the materials, which can have multiple stiffness contributions and multiple relaxation timescales, as in the above examples, while the interplay and relative dominance of their viscoelastic contributions (e.g., the different arms in the Maxwell model) varies greatly with deformation

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

• above the defect in 4t show a reduced minimum, as well as a horizontal shift in position towards the defect centre due to a polaronic distortion induced by the vacancy’s localized negative charge. Molecular dynamics relaxation was unable to capture this effect as part of the modelling, so the ball and

• terminations. The defect free H–Si ball and stick model was the same as used in [43], with defects manually inserted using Avogadro [94][95]. The geometry of the defect atoms within the lattice were optimized using molecular dynamics relaxation with a Merck molecular force field (MMFF94) [96]. Images of the

Influence of the magnetic nanoparticle coating on the magnetic relaxation time

• Mihaela Osaci and
• Matteo Cacciola

Beilstein J. Nanotechnol. 2020, 11, 1207–1216, doi:10.3762/bjnano.11.105

• fill in this gap, this study presents a numerical simulation model that elucidates how the nanoparticle coating affects the nanoparticle agglomeration tendency as well as the effective magnetic relaxation time of the system. To simulate the self-organization of the colloidal nanoparticles, a stochastic

• Langevin dynamics method was applied based on the effective Verlet-type algorithm. The Néel magnetic relaxation time was obtained via the Coffey method in an oblique magnetic field, adapted to the local magnetic field on a nanoparticle. Keywords: colloidal system; effective Verlet-type algorithm; magnetic

• relaxation time; nanoparticle coating; numerical simulation; stochastic Langevin dynamics method; superparamagnetic nanoparticles; Introduction One of the most important biomedical applications of colloidal magnetic nanoparticle systems is magnetic hyperthermia applied as an alternative for cancer treatment

Scanning tunneling microscopy and spectroscopy of rubrene on clean and graphene-covered metal surfaces

• Karl Rothe,
• Alexander Mehler,
• Nicolas Néel and
• Jörg Kröger

Beilstein J. Nanotechnol. 2020, 11, 1157–1167, doi:10.3762/bjnano.11.100

• the hole or electron to the vibrational quantum with energy hν. The Huang–Rhys factor can be expressed as where εν denotes the relaxation energy of the vibration when charging the molecule [10][41]. Comparing the peak height of the orbital signature (I0) with the first vibronic subband (Iν,1) enables

Photothermally active nanoparticles as a promising tool for eliminating bacteria and biofilms

• Mykola Borzenkov,
• Piersandro Pallavicini,
• Angelo Taglietti,
• Laura D’Alfonso,
• Maddalena Collini and
• Giuseppe Chirico

Beilstein J. Nanotechnol. 2020, 11, 1134–1146, doi:10.3762/bjnano.11.98

• nanoparticles produce thermal relaxation, leading to a local increase in the temperature. The overall photothermal effect depends on the irradiation intensity and wavelength, nanoparticle concentration, and the nanoparticle photothermal conversion efficiency [33][38]. It also depends on the type of the

• [78]. Similar to the Prussian blue nanoparticles, CuS nanoparticles display a strong absorption in the NIR region, mainly within the 900–1200 nm range, with an efficient thermal relaxation resulting from the d–d energy band transition of the Cu2+ ions. The very low production costs together with a low

Thermophoretic tweezers for single nanoparticle manipulation

• Jošt Stergar and
• Natan Osterman

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

• measured characteristic cool-down time of the heated region is shorter than 20 ms, which is the typical trap relocation feedback time in the experiment. The calculated thermal relaxation time for the substrate, τ = L2/Dthermal, where L = 10 µm and for sapphire is of the order of 10 μs. Sample imaging is

Applications of superparamagnetic iron oxide nanoparticles in drug and therapeutic delivery, and biotechnological advancements

• Maria Suciu,
• Corina M. Ionescu,
• Alexandra Ciorita,
• Septimiu C. Tripon,
• Dragos Nica,
• Hani Al-Salami and
• Lucian Barbu-Tudoran

Beilstein J. Nanotechnol. 2020, 11, 1092–1109, doi:10.3762/bjnano.11.94

• detection. SPIONs have gained a lot of interest in theranostics, which combines diagnostics and treatment by a single intervention, where they show a lot of promise [64][134][135][136][137][138]. Depending on the dimension of the SPIONs, the heating during hyperthermia is determined by Néel relaxation for

• SPIONs smaller than 10 nm, by Néel and Brownian relaxation for SPIONs between 10 and 13 nm (mechanisms in superparamagnetic nanoparticles), and by hysteresis loss for larger SPIONs (mechanism of ferromagnetic nanoparticles) [139]. Hyperthermia potential and efficacy of SPIONs depend on their structure

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

• TCNQ is located right at the onset of the conduction band. This provides relaxation pathways for electrons tunneling into the LUMO, though still significantly less than on the bare metal. Vibronic excitations of TCNQ on MoS2 on Ag(111) Having shown that the resonances at 470 and 640 mV originate both

• vibrational mode k and n its harmonics. The Huang–Rhys factor is determined by the relaxation energy εk of a vibrational mode when charging the molecule as From the DFT calculations of the TCNQ molecule, we determine all vibrational eigenmodes in the negatively charged state and also derive the Huang–Rhys