Light–matter interactions in two-dimensional layered WSe₂ for gauging evolution of phonon dynamics

• Avra S. Bandyopadhyay,
• Chandan Biswas and
• Anupama B. Kaul

Beilstein J. Nanotechnol. 2020, 11, 782–797, doi:10.3762/bjnano.11.63

• -dimensionality nanocrystallites, the wave function of the optical phonons no longer remains a continuous plane wave and thus the localization of the wave function leads to a relaxation in the conservation of the wave vector selection rules. The phonons with a nonzero wave vector also take part in the Raman

Hexagonal boron nitride: a review of the emerging material platform for single-photon sources and the spin–photon interface

• Stefania Castelletto,
• Faraz A. Inam,
• Shin-ichiro Sato and
• Alberto Boretti

Beilstein J. Nanotechnol. 2020, 11, 740–769, doi:10.3762/bjnano.11.61

• -stable state is a spin-singlet state. The system non-radiatively relaxes between the excited triplet state |2⟩ and the singlet meta-stable state |3⟩. These non-radiative relaxation processes between the different spin states are known as inter-system crossing (ISC). The decay process between the

• criteria for spin–photon-phonon entanglement distribution are high electron spin coherence time T2 (approaching T2 spin-lattice relaxation time) and strain and electrical control of the spin transition and optical transition resonances. The key requirements can be restrictive depending on the applications

• photons exciting electrons to a higher energy level in an atom. This photo-excitation is then followed by various relaxation processes. During these relaxation processes, other photons can be re-irradiated. One interesting parameter is the zero-phonon line (ZPL), which is the difference between the lowest

Effect of substitutional defects on resonant tunneling diodes based on armchair graphene and boron nitride nanoribbons lateral heterojunctions

• Majid Sanaeepur

Beilstein J. Nanotechnol. 2020, 11, 688–694, doi:10.3762/bjnano.11.56

• connected to semi-infinite AGNR contacts at both sides. The energy band edge diagram of the proposed RTD along with the quantized energy level of the well are shown in Figure 1b. Due to small lattice mismatch between graphene and hBN the edge bond relaxation correction for carbon atoms at the interface of C

Observation of unexpected uniaxial magnetic anisotropy in La_2/3Sr_1/3MnO₃ films by a BaTiO₃ overlayer in an artificial multiferroic bilayer

• John E. Ordóñez,
• Lorena Marín,
• Luis A. Rodríguez,
• Pedro A. Algarabel,
• José A. Pardo,
• Roger Guzmán,
• Luis Morellón,
• César Magén,
• Etienne Snoeck,
• María E. Gómez and
• Manuel R. Ibarra

Beilstein J. Nanotechnol. 2020, 11, 651–661, doi:10.3762/bjnano.11.51

• layer are promoted by the large mismatch between the lattice parameters of the BTO and the strained LSMO film (≈2.4%). They correspond to misfit dislocations created parallel and perpendicular to the interface and favor the relaxation of the BTO atomic layers placed far from the BTO/LSMO interface. For

• relaxation of the BTO layer, hence horizontal misfit dislocations are not formed. Similar profiles were extracted from the εzz strain maps. Compared to the εxx, the εzz profiles present noisier behavior inherent to the GPA method [57], with an extended and strong variation around each interface that does not

Comparison of fresh and aged lithium iron phosphate cathodes using a tailored electrochemical strain microscopy technique

• Matthias Simolka,
• Hanno Kaess and
• Kaspar Andreas Friedrich

Beilstein J. Nanotechnol. 2020, 11, 583–596, doi:10.3762/bjnano.11.46

• signal generation magnitude compared to the Vegard expansion or their time scales are much shorter than the relaxation times for ESM experiments (Maxwell relaxation times) [30][32]. Electrochemical side reactions may create surface features, which, however, are detectable by subsequent scans of the same

• signal can be found in Supporting Information File 1. Since the variation of the ESM signal is governed by migration and diffusion processes, it can be used to fit relaxation functions and extract the characteristic time constant τ. Diffusion processes are often fitted using an exponential decay function

• iron dissolution the lower ESM signal is a direct consequence. It is noted that this is probable, as Fe-dissolution has been reported as the prominent degradation mechanism of LFP [9][72][73]. The dynamics of the relaxation process after the dc-voltage pulse are further analysed in Figure 7 and Figure

Luminescent gold nanoclusters for bioimaging applications

• Nonappa

Beilstein J. Nanotechnol. 2020, 11, 533–546, doi:10.3762/bjnano.11.42

• /ethanol (90/10 v/v) mixture compared to that of in pure ethanol solution. In solution, the dynamic intramolecular rotation serves as a route for nonradiative relaxation process. Upon aggregation, the intramolecular rotations are restricted, which blocks the non-radiative pathways and opens the radiative

Interfacial charge transfer processes in 2D and 3D semiconducting hybrid perovskites: azobenzene as photoswitchable ligand

• Nicole Fillafer,
• Tobias Seewald,
• Lukas Schmidt-Mende and
• Sebastian Polarz

Beilstein J. Nanotechnol. 2020, 11, 466–479, doi:10.3762/bjnano.11.38

• combination of azobenzene molecules with conducting or semiconducting materials is of high interest. In connection with semiconductors the occurrence of interesting phenomena has been proposed. The symmetry-allowed π→π* transition and the subsequent structural relaxation can be affected by the electronic

• ligands attached to semiconductors can change conformation under irradiation with light is still a question that is being discussed. Rego et al. simulated a very fast charge transfer from azobenzene to the conduction band of TiO2, followed by a strong vibronic relaxation that excites the N–N stretching

DFT calculations of the structure and stability of copper clusters on MoS₂

• Cara-Lena Nies and
• Michael Nolan

Beilstein J. Nanotechnol. 2020, 11, 391–406, doi:10.3762/bjnano.11.30

• augmented wave potential (PAW) [36]. In the geometry relaxation calculations, all forces acting on the atoms were converged to within 0.02 eV/Å. The bulk structure of MoS2 used in this study was chosen from the “Materials Project” database [37]. The bulk material contains two layers of MoS2. The geometry

• not influenced by the adsorption site. It is of note that the atoms remain at the site where they were originally adsorbed throughout relaxation. This is also apparent from the computed addition energies. The addition of an atom to Cu2 to form a 3D Cu3 cluster is very favourable, with computed

• structures, the atoms remain at their original adsorption site throughout the relaxation for all Cu4 structures. For the linear Cu4 configuration the binding energy at site 1 is only 0.06 eV per Cu more negative than at site 3 and 0.07 eV less negative than at site 2, indicating little difference in

Implementation of data-cube pump–probe KPFM on organic solar cells

• Benjamin Grévin,
• Olivier Bardagot and
• Renaud Demadrille

Beilstein J. Nanotechnol. 2020, 11, 323–337, doi:10.3762/bjnano.11.24

• electron–hole annihilation at the D–A interfaces. Here, we do not discuss the losses by exciton relaxation or by pairwise recombination of the CT state. The free carriers can also be trapped in tail states [25] before recombining with free unpaired counter charges. This slower recombination process is

Facile biogenic fabrication of hydroxyapatite nanorods using cuttlefish bone and their bactericidal and biocompatibility study

• Satheeshkumar Balu,
• Manisha Vidyavathy Sundaradoss,
• Swetha Andra and
• Jaison Jeevanandam

Beilstein J. Nanotechnol. 2020, 11, 285–295, doi:10.3762/bjnano.11.21

• ]. Thus, it is evident that the reaction at basic pH conditions and a temperature of 80 °C supports the relaxation of aragonite calcium carbonate bonds to form calcite structure in 3 h [24]. It can be noted from the diffraction peaks that the formation of Hap crystal growth was initiated at 6 h of

Nonequilibrium Kondo effect in a graphene-coupled quantum dot in the presence of a magnetic field

• Levente Máthé and
• Ioan Grosu

Beilstein J. Nanotechnol. 2020, 11, 225–239, doi:10.3762/bjnano.11.17

• potential. This electron transfer determines a finite relaxation time τσ, that can be calculated using second-order perturbation theory [12][13]. It can be intuitively introduced by substituting δ in the self-energies Σiσ(ω) with [31][34]. By considering a small value for e.g., = δ ≈ 10−7 [31], the

The effect of heat treatment on the morphology and mobility of Au nanoparticles

• Sven Oras,
• Sergei Vlassov,
• Simon Vigonski,
• Boris Polyakov,
• Mikk Antsov,
• Vahur Zadin,
• Rünno Lõhmus and
• Karine Mougin

Beilstein J. Nanotechnol. 2020, 11, 61–67, doi:10.3762/bjnano.11.6

• twinned NPs and the tendency of such particles to seek mechanisms of stress relaxation [25]. The rearrangement of surface atoms into more rounded outer geometries can be a way of energy minimization while preserving the five-fold twinned inner structure of the NP, as shown in Figure 3 for a Au NP heated

Fully amino acid-based hydrogel as potential scaffold for cell culturing and drug delivery

• Dávid Juriga,
• Evelin Sipos,
• Orsolya Hegedűs,
• Gábor Varga,
• Miklós Zrínyi,
• Krisztina S. Nagy and
• Angéla Jedlovszky-Hajdú

Beilstein J. Nanotechnol. 2019, 10, 2579–2593, doi:10.3762/bjnano.10.249

• induced by the cleavage of the disulfide bonds. The change of the ionic strength is a faster process, therefore, the relaxation time determined for the 0CYS-LYS hydrogel is smaller than that of the 20CYS-LYS hydrogel. Dependence of the swelling degree of the PASP-20CYS-LYS gels on the amount of DTT in the

Formation of metal/semiconductor Cu–Si composite nanostructures

• Natalya V. Yumozhapova,
• Andrey V. Nomoev,
• Vyacheslav V. Syzrantsev and
• Erzhena C. Khartaeva

Beilstein J. Nanotechnol. 2019, 10, 2497–2504, doi:10.3762/bjnano.10.240

• relaxation of the initial state at a temperature T = 1800 K. The cluster was cooled to a temperature of 300 K within the framework of the canonical ensemble using the Nose thermostat. The time step was τ = 1 fs. The cooling rate is 1 K/ps (1012 K/s). For the calculation, we used the speed variant of the

Abrupt elastic-to-plastic transition in pentagonal nanowires under bending

• Sergei Vlassov,
• Magnus Mets,
• Boris Polyakov,
• Jianjun Bian,
• Leonid Dorogin and
• Vahur Zadin

Beilstein J. Nanotechnol. 2019, 10, 2468–2476, doi:10.3762/bjnano.10.237

• evolution of atoms are within the framework of canonical (NVT) ensembles, and the time step is chosen as 2.0 fs. The Nosé–Hoover thermostat is used to adjust the temperature of the atomic system to around 300 K [37][38]. After construction of the NW, structural relaxation is firstly performed by using a

Coating of upconversion nanoparticles with silica nanoshells of 5–250 nm thickness

• Cynthia Kembuan,
• Maysoon Saleh,
• Bastian Rühle,
• Ute Resch-Genger and
• Christina Graf

Beilstein J. Nanotechnol. 2019, 10, 2410–2421, doi:10.3762/bjnano.10.231

• as -OH groups from ethanol and maybe also from silanol or silanolate groups of the silica network. The increase in non-radiative relaxation processes by surface quenching effects caused for example by Igepal CO-520 after silica coating can lead to a decrease of the UCL intensity [66]. The

Design of a nanostructured mucoadhesive system containing curcumin for buccal application: from physicochemical to biological aspects

• Sabrina Barbosa de Souza Ferreira,
• Gustavo Braga,
• Évelin Lemos Oliveira,
• Jéssica Bassi da Silva,
• Hélen Cássia Rosseto,
• Lidiane Vizioli de Castro Hoshino,
• Mauro Luciano Baesso,
• Wilker Caetano,
• Craig Murdoch,
• Helen Elizabeth Colley and
• Marcos Luciano Bruschi

Beilstein J. Nanotechnol. 2019, 10, 2304–2328, doi:10.3762/bjnano.10.222

• previously for polymer blends containing P407 and other acrylic acid derivative with a similar cross-linking degree as C974P to carry hypericin [69]. In this study, the polymeric micelle relaxation due to the hydrophobic drug could explain this behavior and be related to the low yield values in the flow

• , hence, the polymeric chains were slowly reorganized, whereas CUR diffused by time-dependent anomalous effects. The solvent diffusion velocity displayed similar relaxation of the polymeric chains [77]. Ex vivo permeation of curcumin in porcine oral mucosa Permeation studies are considered fundamental to

Nitrogen-vacancy centers in diamond for nanoscale magnetic resonance imaging applications

• Alberto Boretti,
• Lorenzo Rosa,
• Jonathan Blackledge and
• Stefania Castelletto

Beilstein J. Nanotechnol. 2019, 10, 2128–2151, doi:10.3762/bjnano.10.207

• performance. Nano-MRI employing nuclear spins is limited by the spin–lattice relaxation time. This time is longer in singlet states. It affects the chance of using weak spin–spin interactions and hyperpolarized media. The symmetry mismatch between singlet and triplet states prevents interaction so that

• singlet relaxation can only be mediated by higher-order weak processes, making use of adjacent spins which give the same difference bars as radio frequency (RF) access to singlet states. M2S and spin-lock induced crossing (SLIC) [14] are examples of pulse sequences to circumvent this limitation

• (spin–lattice relaxation) times of many hours. This is an advantage compared to other liquid-phase compounds as hyperpolarized 13C spins usually relax on timescales of T1 ≈60 s to thermal equilibrium. In [18], synthetic, inexpensive, commercial ND with a diameter ranging from a micrometer to 25 nm were

Synthesis of highly active ETS-10-based titanosilicate for heterogeneously catalyzed transesterification of triglycerides

• Muhammad A. Zaheer,
• David Poppitz,
• Khavar Feyzullayeva,
• Marianne Wenzel,
• Jörg Matysik,
• Radomir Ljupkovic,
• Aleksandra Zarubica,
• Alexander A. Karavaev,
• Andreas Pöppl,
• Roger Gläser and
• Muslim Dvoyashkin

Beilstein J. Nanotechnol. 2019, 10, 2039–2061, doi:10.3762/bjnano.10.200

Improvement of the thermoelectric properties of a MoO₃ monolayer through oxygen vacancies

• Wenwen Zheng,
• Wei Cao,
• Ziyu Wang,
• Huixiong Deng,
• Jing Shi and
• Rui Xiong

Beilstein J. Nanotechnol. 2019, 10, 2031–2038, doi:10.3762/bjnano.10.199

• charge and T is the absolute temperature. Σ(ε) is the so-called transport distribution function [24]: where is the group velocity of the carriers and is the relaxation time. The thermal conductivity κe is obtained by the Wiedemann–Franz law: κe = LσT, where L is the Lorenz number. For the calculation

• of the relaxation time τ, we apply the deformation potential (DP) theory [25] where τ is estimated by τ = μm*/e. The carrier mobility μ2D in 2D materials is given by Where m* is the effective mass and md is the density of states (DOS) mass determined by E1 is the DP constant and C2D is the elastic

• be explained by the proportionality of the Seebeck coefficient to the bandgap [33]. Unlike the Seebeck coefficient, the electrical and thermal conductivities exhibit a clear anisotropic behavior which is attributed to the anisotropic relaxation time [17]. Figure 2b reveals that the electrical

Gold-coated plant virus as computed tomography imaging contrast agent

• Alaa A. A. Aljabali,
• Mazhar S. Al Zoubi,
• Khalid M. Al-Batanyeh,
• Ali Al-Radaideh,
• Mohammad A. Obeid,
• Abeer Al Sharabi,
• Walhan Alshaer,
• Bayan AbuFares,
• Tasnim Al-Zanati,
• Murtaza M. Tambuwala,
• Naveed Akbar and
• David J. Evans

Beilstein J. Nanotechnol. 2019, 10, 1983–1993, doi:10.3762/bjnano.10.195

• contrast agents achieve their effect by increasing the relaxation rates (longitudinal relaxation rate (R1), transverse relaxation rate (R2), and pseudo-transverse relaxation rate (R2*)) of water protons in tissues through the catalysis of alignment of nuclear spins [1], thus manipulating the MR image

• contrast. This effect is known as paramagnetic relaxation enhancement [2] and is common among contrast agents containing gadolinium [3] and iron oxide nanoparticles [4]. CT is a non-invasive, diagnostic imaging tool that allows for 3-D visual reconstruction and tissue segmentation. It relies on the use of

Magnetic properties of biofunctionalized iron oxide nanoparticles as magnetic resonance imaging contrast agents

• Natalia E. Gervits,
• Andrey A. Gippius,
• Alexey V. Tkachev,
• Evgeniy I. Demikhov,
• Sergey S. Starchikov,
• Igor S. Lyubutin,
• Alexander L. Vasiliev,
• Vladimir P. Chekhonin,
• Maxim A. Abakumov,
• Alevtina S. Semkina and
• Alexander G. Mazhuga

Beilstein J. Nanotechnol. 2019, 10, 1964–1972, doi:10.3762/bjnano.10.193

• . The contrast between the tissues in MRI images depends on their properties such as fat and water content as well as on the sequence of the procedure parameters. There are three main characteristics that determine the contrast of the image: 1) proton density; 2) the spin–lattice relaxation time T1; and

• 3) the spin–spin relaxation time T2. Generally, these natural differences in tissue properties provide the necessary contrast, but in some cases, the pathological focus cannot be visualized in the images, for instance, due to size effects or the difficulty in delineating boundaries to determine

• containing paramagnetic gadolinium, reduce the spin–lattice relaxation time (T1), which makes the pathological focus brighter. Negative contrast agents typically contain MNPs with Fe2+ and Fe3+ ions. They reduce the T2 relaxation time and therefore weaken the signal from the tissues that absorbed the agent

Pulsed laser synthesis of highly active Ag–Rh and Ag–Pt antenna–reactor-type plasmonic catalysts

• Kenneth A. Kane and
• Massimo F. Bertino

Beilstein J. Nanotechnol. 2019, 10, 1958–1963, doi:10.3762/bjnano.10.192

• of femtoseconds before relaxation, which is sufficient for chemical transformation or additional vibrational energy to be transferred to the adsorbate, leading to reaction [14]. There are two mechanisms that can lead to the electronic excitation in the adsorbate–metal complex. The first is the

First principles modeling of pure black phosphorus devices under pressure

• Ximing Rong,
• Zhizhou Yu,
• Zewen Wu,
• Junjun Li,
• Bin Wang and
• Yin Wang

Beilstein J. Nanotechnol. 2019, 10, 1943–1951, doi:10.3762/bjnano.10.190

• found that the armchair BP device can be used as a pressure sensor, while the zigzag BP device cannot be used in that way when the pressure ratio is less than 15%. This is the core conclusion of this work. To examine the influence of structural relaxation, the conductance of two fully relaxed zigzag and

Charge-transfer interactions between fullerenes and a mesoporous tetrathiafulvalene-based metal–organic framework

• Manuel Souto,
• Joaquín Calbo,
• Samuel Mañas-Valero,
• Aron Walsh and
• Guillermo Mínguez Espallargas

Beilstein J. Nanotechnol. 2019, 10, 1883–1893, doi:10.3762/bjnano.10.183

• details). We initially modelled the fullerene C60 guest in the middle of the MUV-2 mesopore. After several relaxation steps, the C60 was able to accommodate in one of the three cavities to interact favourably with the TTF-based ligand. We explored two possible conformations for the host–guest C60@MUV-2