Exploring surface charge dynamics: implications for AFM height measurements in 2D materials

• Mario Navarro-Rodriguez,
• Andres M. Somoza and
• Elisa Palacios-Lidon

Beilstein J. Nanotechnol. 2024, 15, 767–780, doi:10.3762/bjnano.15.64

• height measurements in AM-AFM mode, the presence of an oscillating surface charge introduces additional dynamic effects typically overlooked, which, under certain conditions, should be considered when calculating the tip–sample interaction. Also, we have identified a relaxation time required to reach the

• stationary or periodic state for a static or oscillating tip, respectively. This relaxation time is crucial to the overall charge dynamics and depends on the material’s in-plane conductivity and on the measurement parameters. When this relaxation time is comparable to, or even significantly exceeds, the

Radiofrequency enhances drug release from responsive nanoflowers for hepatocellular carcinoma therapy

• Yanyan Wen,
• Ningning Song,
• Yueyou Peng,
• Weiwei Wu,
• Qixiong Lin,
• Minjie Cui,
• Rongrong Li,
• Qiufeng Yu,
• Sixue Wu,
• Yongkang Liang,
• Wei Tian and
• Yanfeng Meng

Beilstein J. Nanotechnol. 2024, 15, 569–579, doi:10.3762/bjnano.15.49

• concentrations of NFs (0, 2, 4, 6, and 8 mM), which were subsequently placed into 1.5 mL Eppendorf tubes. The samples were then placed in a 3.0 T MRI scanner to determine the longitudinal relaxation time (T1) and the transversal relaxation time (T2). The images were acquired by T1/T2 mapping sequences using the

Ultrasensitive and ultrastretchable metal crack strain sensor based on helical polydimethylsiloxane

• Shangbi Chen,
• Dewen Liu,
• Weiwei Chen,
• Huajiang Chen,
• Jiawei Li and
• Jinfang Wang

Beilstein J. Nanotechnol. 2024, 15, 270–278, doi:10.3762/bjnano.15.25

• remarkable stability and favorable recoverability. Figure 2d illustrates the response time of the helical sensor when subjected to a quasi-transient step strain of 10%. Notably, the response time was approximately 158 ms, while the relaxation time was approximately 243 ms, indicating a strong response to

A bifunctional superconducting cell as flux qubit and neuron

• Dmitrii S. Pashin,
• Pavel V. Pikunov,
• Marina V. Bastrakova,
• Andrey E. Schegolev,
• Nikolay V. Klenov and
• Igor I. Soloviev

Beilstein J. Nanotechnol. 2023, 14, 1116–1126, doi:10.3762/bjnano.14.92

• operating temperatures. For example, the dark blue region in Figure 4b is only suitable for T ∼ 0.1 K. Note that for the parameters used and a Josephson junction quality factor of Q ∼ 105, the relaxation time is tr ∼ 1 μs. From this rough estimate it can be seen that in the future, adiabatic cells of tuning

Plasmonic nanotechnology for photothermal applications – an evaluation

• A. R. Indhu,
• L. Keerthana and
• Gnanaprakash Dharmalingam

Beilstein J. Nanotechnol. 2023, 14, 380–419, doi:10.3762/bjnano.14.33

• product of ωτ, where τ is the relaxation time of the free electron gas) is much higher than unity, thus leading to an approximation that there is no damping. Hence ignoring the damping term in Equation 5, we get It follows also that under plasmon resonance conditions ε1 < −εm, εm is the dielectric

• distribution. The electromagnetic absorptivity of the metal conduction electrons is proportional to the rate of momentum transfer to the lattice. It can be written as [64]: m* is the effective electron mass, n is the electron density, and τeff is the conduction electron relaxation time given by τ is the

• conductivity relaxation time with temperatures T larger than the Debye temperature Θ. The Debye temperature is the temperature of a crystal’s highest mode of vibration. The decay of the excited electrons (plasmons) is through either radiative relaxation (i.e., photon emission) or non-radiative relaxation. Non

Spin dynamics in superconductor/ferromagnetic insulator hybrid structures with precessing magnetization

• Yaroslav V. Turkin and
• Nataliya Pugach

Beilstein J. Nanotechnol. 2023, 14, 233–239, doi:10.3762/bjnano.14.22

• . In metals, such a penetration is limited by the spin flip scattering, while inside the superconductor, the spin relaxation time is usually much longer. Thus, induced magnetization and spin current in our problem are determined mainly by the competition between spin singlet and spin triplet orders [34

Characterisation of a micrometer-scale active plasmonic element by means of complementary computational and experimental methods

• Ciarán Barron,
• Giulia Di Fazio,
• Samuel Kenny,
• Silas O’Toole,
• Robin O’Reilly and
• Dominic Zerulla

Beilstein J. Nanotechnol. 2023, 14, 110–122, doi:10.3762/bjnano.14.12

• information extracted in both cases does not depend on the drive frequency, given the thermal relaxation time of such a metallic element on a sapphire substrate is of the order of nanoseconds, and as such there is no need for matching drive frequencies. AFM scans were performed on a 30 × 30 μm2 window with a

The influence of structure and local structural defects on the magnetic properties of cobalt nanofilms

• Alexander Vakhrushev,
• Aleksey Fedotov,
• Olesya Severyukhina and
• Anatolie Sidorenko

Beilstein J. Nanotechnol. 2023, 14, 23–33, doi:10.3762/bjnano.14.3

• cobalt atom spins for ideal crystal hexagonal close-packed lattice (a), (b), (c) and nanofilm structure (d), (e), (f) formed in the numerical experiment at a deposition temperature of 300 K, spin relaxation time 100 ps, and external magnetic field value of 1.0 T. Changes in spin temperature under a

Structural studies and selected physical investigations of LiCoO₂ obtained by combustion synthesis

• Monika Michalska,
• Paweł Ławniczak,
• Tomasz Strachowski,
• Adam Ostrowski and
• Waldemar Bednarski

Beilstein J. Nanotechnol. 2022, 13, 1473–1482, doi:10.3762/bjnano.13.121

• flattening of the semicircle caused by the distribution of the relaxation time constants. Ideally, when only one time constant describes relaxation processes in the material (Debye-type response), the fit parameter α is close to 0 and there is no flattening of the semicircle. The distribution of the time

Ultrafast signatures of magnetic inhomogeneity in Pd_1−xFe_x (x ≤ 0.08) epitaxial thin films

• Andrey V. Petrov,
• Sergey I. Nikitin,
• Lenar R. Tagirov,
• Amir I. Gumarov,
• Igor V. Yanilkin and
• Roman V. Yusupov

Beilstein J. Nanotechnol. 2022, 13, 836–844, doi:10.3762/bjnano.13.74

• negative component increases in absolute value. Also, both the amplitude and the relaxation time of the slow positive component decrease. At temperatures of 90 and 160 K, another slow negative component appears in the samples with 6 and 8 atom % of iron, respectively. Its relaxation time is about 1 ns. The

• components, obtained from the fit of the experimental data with Equation 1 and Equation 2, are presented in Figure 3 and Figure 4 for the reflectivity and time-resolved MOKE, respectively. We note here the invariance of the amplitude As (Figure 3a) and relaxation time (Figure 3b) at T ≥ TC, and a kink in

• samples with 6.2 and 8.0 atom % of iron. For the sample with 3.8 atom % of iron, it has the same behavior down to 150 K, and then decreases to zero at the lowest temperatures. The relaxation time of this component is practically independent of the temperature and is = 0.80 ± 0.10 ps. Figure 4a shows the

Impact of electron–phonon coupling on electron transport through T-shaped arrangements of quantum dots in the Kondo regime

• Patryk Florków and
• Stanisław Lipiński

Beilstein J. Nanotechnol. 2021, 12, 1209–1225, doi:10.3762/bjnano.12.89

• hopping term between the open and interacting dot is also renormalized by a factor X, which describes the effect of the phonon cloud accompanying the hopping process . For l = 1 both hopping integrals are renormalized and . Assuming the relaxation time of phonons to be much shorter than the time of

First-principles study of the structural, optoelectronic and thermophysical properties of the π-SnSe for thermoelectric applications

• Muhammad Atif Sattar,
• Najwa Al Bouzieh,
• Maamar Benkraouda and
• Noureddine Amrane

Beilstein J. Nanotechnol. 2021, 12, 1101–1114, doi:10.3762/bjnano.12.82

• Gibbs2 code [54] by considering lattice vibrations. To calculate the thermoelectric properties, we used the Boltzmann transport theory employed in the BoltzTrap2 [55] code by utilizing the rigid band estimation under a constant relaxation time. Results and Discussion Structural properties We have

• following relations [9]: Here, f0(T,ε) is the Fermi distribution function, α and β are tensor indices, Ω is cell volume, and σαβ(ε) is the electrical conductivity tensor computed through Fourier interpolation of the band energies. We have evaluated these TE parameters under a constant relaxation time (τ

• ambient condition, the value of (κe) is observed to be 0.30 × 1018 W·K−1·m−1 for the cubic π-SnSe alloy under a constant relaxation time (1014). The thermal conductivity linearly increases with the increasing temperature which can be also seen from Figure 9c and has a relatively similar linear increase

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

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

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

• shown in Figure 2 was calculated is limited by the maximum time of the breath test. However, the total exposure time and relaxation time of the majority of the breath tests did not reach 180 s and the missing points of the response curves were assigned zero values. Thus, the characteristic time interval

• -contact sensor profile). Vs is the voltage decrease that occurs in the sensor, t is the time, t1 is the exposure time, and t2 is the relaxation time. Temporal dependence of the absolute values of the correlation coefficient |r|. Here, r describes the correlation between the response voltage values of the

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

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

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

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

• longitudinal (r1) and transverse (r2) sample relaxation time rates were measured to evaluate the properties of the dual-mode contrast agents. Fe3O4-DHCA and Gd2O3-DHCA were used as controls at different concentrations: 0, 20, 58, 74, and 96 μg/mL and 0, 1.6, 4.8, 6, and 8 μg/mL, respectively. The nanoparticles

• were diluted in normal saline and their relaxation time rates were measured using the 3.0 T magnetic resonance scanner with a 15-channel knee coil with T1-weighted imaging (TR/TE = 1000/11 ms) and T2-weighted imaging (TR/TE = 4000/70 ms). Cytotoxicity assay L929 cells were seeded onto a 96-well plate

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

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

• 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

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

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

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

• timescales of 53 min. DNP was also used at 4 K and a nuclear polarization of 8% was achieved in larger micrometer-sized diamonds. However, the spin relaxation time was not increased. Hyperpolarization at room temperature for 350 nm NDs in water provided an enhanced 13C nuclear spin resonance signal, with

• standard inductive NMR technique. An enhancement in the detection of 1H of −4 over the thermal 1H spectrum is achieved. This enhancement is mostly in 125 nm NDs rather than in 18 nm, and it is larger for higher concentrations. However, the relaxation time is shorter at higher ND concentrations. This is not