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

Gas-sensing features of nanostructured tellurium thin films

• Dumitru Tsiulyanu

Beilstein J. Nanotechnol. 2020, 11, 1010–1018, doi:10.3762/bjnano.11.85

• time delay between measurements was 2 s, which was, simultaneously, much smaller than the sensor response time and much higher than the assessed dielectric relaxation time value. In order to transform the resistance signal into a voltage signal, the sample was connected in series to a load resistance

• dielectric relaxation time (τr). As τr = εε0ρ (ρ is the bulk resistivity, ε and ε0 are the permittivity and the electric constant, respectively), it is clear that τr decreases since there is a reduction in the resistivity when the temperature increase and the system reaches steady state in less time. Another

Uniform Fe₃O₄/Gd₂O₃-DHCA nanocubes for dual-mode magnetic resonance imaging

• Miao Qin,
• Yueyou Peng,
• Mengjie Xu,
• Hui Yan,
• Yizhu Cheng,
• Xiumei Zhang,
• Di Huang,
• Weiyi Chen and
• Yanfeng Meng

Beilstein J. Nanotechnol. 2020, 11, 1000–1009, doi:10.3762/bjnano.11.84

• ) were homogeneously distributed throughout the Fe3O4/Gd2O3-DHCA (FGDA) nanocubes. Relaxation time analysis was performed on the images obtained from the 3.0 T scanner. The results demonstrated that r1 and r2 maximum values were 67.57 ± 6.2 and 24.2 ± 1.46 mM−1·s−1, respectively. In vivo T1- and T2

• researchers have been developing strategies to synthesize contrast agents [6][7][8][9]. MRI contrast agents can interact with the hydrogen protons that are present in the surrounding tissue, shortening their relaxation times and leading to signal changes [10]. Generally, contrast agents can be divided into

• two categories depending on the effect they have on MRI. T1 contrast agents shorten longitudinal relaxation times, generating bright signals [11][12][13][14][15], whereas T2 contrast agents shorten transverse relaxation times, generating dark signals [16][17]. Even though T1 contrast agents, such as

Electrochemical nanostructuring of (111) oriented GaAs crystals: from porous structures to nanowires

• Elena I. Monaico,
• Eduard V. Monaico,
• Veaceslav V. Ursaki,
• Shashank Honnali,
• Vitalie Postolache,
• Karin Leistner,
• Kornelius Nielsch and
• Ion M. Tiginyanu

Beilstein J. Nanotechnol. 2020, 11, 966–975, doi:10.3762/bjnano.11.81

• of the Figure 7A. The photocurrent build-up and relaxation for a photodetector produced on a nanowire with a diameter of 400 nm is presented in Figure 7B for an IR illumination density of 800 mW·cm−2. One can see that the current increases by a factor of four in magnitude under illumination with IR

• nanowires is related to their long-relaxation phenomena caused by the strong surface band bending effects [37]. In contrast, much shorter relaxation times are inherent to photodetectors based on interdigitated metal–semiconductor–metal structures with Schottky diodes. However, a very low feature size is

• shutter was used in the relaxation experiments. The signal from the source measure unit was fed to computer via IEEE-488 interface for further data processing. The measurements were performed at 300 K. SEM images in cross section of porous GaAs layers for three different conditions of anodization in 1.75

Band tail state related photoluminescence and photoresponse of ZnMgO solid solution nanostructured films

• Vadim Morari,
• Aida Pantazi,
• Nicolai Curmei,
• Vitalie Postolache,
• Emil V. Rusu,
• Marius Enachescu,
• Ion M. Tiginyanu and
• Veaceslav V. Ursaki

Beilstein J. Nanotechnol. 2020, 11, 899–910, doi:10.3762/bjnano.11.75

• long duration relaxation of photoconductivity was shown to be characteristic for films prepared by spin coating, while a fast response to irradiation was observed in samples prepared by aerosol spray pyrolysis. Similar to the issues about the influence of the technology on the morphology of films

• to the higher concentration of acceptor levels introduced during spin coating. Long duration relaxation of photoconductivity and persistent photoconductivity was previously observed in highly doped and compensated semiconductors [39], porous semiconductors [48] and solid solutions [40]. The origin of

• fluctuations lead to the formation of potential barriers, which have to be overcome for the recombination of photoexcited carrier to occur during the relaxation processes. On the other hand, the mechanisms for attaining such potential fluctuations were found to be different. In highly doped semiconductors, the

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

• ) and, thus, kx(y) as a function of Pfib. In this procedure it is not needed to take into account the small correction of σΔx(Δy) due to motion blurring [13], in view of the short integration time of the camera compared to the trap relaxation time. To obtain plots of kx(y) as a function of Ptrap, we

Adsorption behavior of tin phthalocyanine onto the (110) face of rutile TiO₂

• Lukasz Bodek,
• Mads Engelund,
• Aleksandra Cebrat and
• Bartosz Such

Beilstein J. Nanotechnol. 2020, 11, 821–828, doi:10.3762/bjnano.11.67

• nonplanar Pc molecule. As a result, the abovementioned relaxation of a Sn-down Pc molecule leads to an increase in the dipole moment from −0.6 D for gas-phase SnPc to −1.13 D for relaxed SnPc. This effect is mainly due to a change of the position of positively charged H atoms at the periphery of the

• molecular adsorbate and the substrate, as was presented for CuTPP on rutile (110) [33]. The charge state of a CuTPP molecule depends on the particular localization of hydroxy groups under the molecule. For Sn-down Pc molecules, the relaxation brings the macrocycle closer to the surface, which increases long