Modulated critical currents of spin-transfer torque-induced resistance changes in NiCu/Cu multilayered nanowires

• Mengqi Fu,
• Roman Hartmann,
• Julian Braun,
• Sergej Andreev,
• Torsten Pietsch and
• Elke Scheer

Beilstein J. Nanotechnol. 2024, 15, 360–366, doi:10.3762/bjnano.15.32

• opposite direction (negative magnetic fields) It makes Heff on layer 2 negative even when µ0H is slightly positive; it becomes more negative during the downward sweep of µ0H. The damping term in the Landau–Lifshitz–Gilbert–Slonczewski equation increases as Heff becomes larger. Therefore, as long as

Design, fabrication, and characterization of kinetic-inductive force sensors for scanning probe applications

• August K. Roos,
• Ermes Scarano,
• Elisabet K. Arvidsson,
• Erik Holmgren and
• David B. Haviland

Beilstein J. Nanotechnol. 2024, 15, 242–255, doi:10.3762/bjnano.15.23

• interferometric and beam-deflection detectors of motion are sufficient to resolve the thermal noise force determined by the damping of the cantilever eigenmode in thermal equilibrium with its environment. Operation in high vacuum and at cryogenic temperatures reduces this force noise, improving sensitivity to the

• temperature of the mechanical mode, and the damping coefficient is expressed as the product of the effective mass meff and the linewidth γm of the mechanical resonance. Decreasing temperature and damping improves force sensitivity. It is important to understand the sources of damping for cryogenic AFM, where

• cantilevers oscillate in vacuum. Force sensitivity will improve with smaller meff only if mechanisms of damping, such as clamping loss and surface effects, do not increase disproportionately. The detection scheme imprints the mechanical motion into the field of the microwave resonator, leading to motional

Ferromagnetic resonance spectra of linear magnetosome chains

• Elizaveta M. Gubanova and
• Nikolai A. Usov

Beilstein J. Nanotechnol. 2024, 15, 157–167, doi:10.3762/bjnano.15.15

• chain, the distance between the centers of neighboring particles, the mutual orientation of the cubic axes of particle anisotropy, and the value of the magnetic damping constant is studied. It is shown that FMR spectra of non-oriented chain assemblies depend on the average particle diameter at a fixed

• thickness of the lipid magnetosome membrane, as well as on the value of the magnetic damping constant. At the same time, they are practically independent of the number Np of particles in the chain under the condition Np ≥ 10. The FMR spectra of non-oriented assemblies of magnetosome chains are compared with

• of the i-th single-domain nanoparticle of the chain is governed by the stochastic Landau–Lifshitz equation [29][30][31][32], where γ is the gyromagnetic ratio, γ1 = γ/(1 + κ2), κ is the magnetic damping constant, is the effective magnetic field, and is the thermal field. The effective magnetic

Current-induced mechanical torque in chiral molecular rotors

• Richard Korytár and
• Ferdinand Evers

Beilstein J. Nanotechnol. 2023, 14, 711–721, doi:10.3762/bjnano.14.57

• delivers the equation for a rotor in the limit m = 0. We have added a phenomenological damping term to the EOM (which does not follow from the conservative Lagrangian formalism). The damping term is zero in all numerical results of this work unless stated explicitly. When V = γ = 0, the equation expresses

• EOM dimensionless, where now the dots indicate differentiation with respect to and we defined , which is a quantity of the order of unity, and is a dimensionless damping rate. Notice the appearance of the small parameter , which, however, is here often multiplied by the large velocity . EOM for the

Suspension feeding in Copepoda (Crustacea) – a numerical model of setae acting in concert

• Alexander E. Filippov,
• Wencke Krings and
• Stanislav N. Gorb

Beilstein J. Nanotechnol. 2023, 14, 603–615, doi:10.3762/bjnano.14.50

• practically independently of one another. Thus, particles do not interact directly with each other in our model. However, each particle interacts with the setae via the liquid. Due to strong damping, each particle tends to equilibrate its speed with the local velocity of the liquid. This velocity, in turn, is

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

• contributions to the plasmon damping of different scattering phenomena, the different scattering processes of the oscillating plasmons, and the screening between the plasmons and the restoring nuclear forces [33][34]. The proximity among LSPR-active nanoparticles is also a major factor. Indeed, combined effects

• Equation 3 to the general constitutive relation for a linear isotropic material given by Equation 4, we get the relation in Equation 5. εr is the relative permittivity of the material and ε0 the permittivity of free space. For frequencies close to ωp, the temporal duration of damping (quantified by the

• 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

A distributed active patch antenna model of a Josephson oscillator

• Vladimir M. Krasnov

Beilstein J. Nanotechnol. 2023, 14, 151–164, doi:10.3762/bjnano.14.16

• sine-Gordon equation, It follows from Equation 1 and Equation 2, taking into account the ac-Josephson relation, V = (Φ0/2π)∂η/∂t. Equation 3 is written in a dimensionless form with space, = x/λJ, normalized by λJ,and time, = ωpt, by the Josephson plasma frequency, ωp. Here α is the QP damping factor

• saturation of the amplitude for α→0, although at a value of 4 instead of π. Thus, Equation 30 provides a simple and sufficiently good approximation for a significantly broader range of damping parameters than Equation 25. Input resistance For the practically most important velocity matching mode, kn = k

• radiative losses, Using definitions of α and Q, we can introduce a total damping factor where the total resistance is Thus, to include radiative losses, α and RQP in the equations above should be replaced by αtot and Rtot. For the n-th cavity mode resonance we obtain, For the most important velocity

Nonlinear features of the superconductor–ferromagnet–superconductor φ₀ Josephson junction in the ferromagnetic resonance region

• Aliasghar Janalizadeh,
• Ilhom R. Rahmonov,
• Sara A. Abdelmoneim,
• Yury M. Shukrinov and
• Mohammad R. Kolahchi

Beilstein J. Nanotechnol. 2022, 13, 1155–1166, doi:10.3762/bjnano.13.97

• characteristics of a φ0 Josephson junction in the ferromagnetic resonance region. We show that at small values of the system parameters damping, spin–orbit interaction, and Josephson-to-magnetic energy ratio, the magnetic dynamics is reduced to the dynamics of a scalar Duffing oscillator driven by the Josephson

• oscillations. The role of the increasing superconducting current in the resonance region is clarified. Shifting of the ferromagnetic resonant frequency and the reversal of its damping dependence due to nonlinearity are demonstrated by the full Landau–Lifshitz–Gilbert–Josephson system of equations and in its

• oscillator describes several effects in other models, too [17]. One example are the resonance effects in the antiferromagnetic bimeron in response to an alternating current, which has applications in the detection of weak signals [15][18][19]. The Gilbert damping term is added phenomenologically to the

A cantilever-based, ultrahigh-vacuum, low-temperature scanning probe instrument for multidimensional scanning force microscopy

• Hao Liu,
• Zuned Ahmed,
• Sasa Vranjkovic,
• Manfred Parschau,
• Andrada-Oana Mandru and
• Hans J. Hug

Beilstein J. Nanotechnol. 2022, 13, 1120–1140, doi:10.3762/bjnano.13.95

• suspension springs that reach through cylindrical tubes running through the LHe tank and are mounted on top of the tank. Together with the Eddy current damping system mounted at the bottom of the cryostat, this provides excellent vibration isolation such that a tip–sample gap stability better than 1 pm can

Influence of water contamination on the sputtering of silicon with low-energy argon ions investigated by molecular dynamics simulations

• Grégoire R. N. Defoort-Levkov,
• Alan Bahm and
• Patrick Philipp

Beilstein J. Nanotechnol. 2022, 13, 986–1003, doi:10.3762/bjnano.13.86

• below the sample in the z-direction. The different axes are defined in Figure 2. The simulations for sample preparation were run in an NVT ensemble using the Langevin thermostat with a damping parameter set to 100 time steps and the temperature set to 300 K [53]. The pristine sample was equilibrated

Comparing the performance of single and multifrequency Kelvin probe force microscopy techniques in air and water

• Jason I. Kilpatrick,
• Emrullah Kargin and
• Brian J. Rodriguez

Beilstein J. Nanotechnol. 2022, 13, 922–943, doi:10.3762/bjnano.13.82

• addition, the positioning of the cantilever close to the surface will increase the damping on the cantilever and alter the transfer function accordingly [103]. Under conditions where the tip starts tapping the surface, the linearity of the amplitude signal in response to VAC and/or VCPD may be disrupted

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

• inhomogeneities cause spin-flip and pairing wave function damping, thus, reducing the magnitude of the Josephson critical current. Small-scale inhomogeneities are difficult to detect with either conventional neutron-scattering methods [34] or with the stationary magneto-optical Kerr/Faraday effect and

A superconducting adiabatic neuron in a quantum regime

• Marina V. Bastrakova,
• Dmitrii S. Pashin,
• Dmitriy A. Rybin,
• Andrey E. Schegolev,
• Nikolay V. Klenov,
• Igor I. Soloviev,
• Anastasiya A. Gorchavkina and
• Arkady M. Satanin

Beilstein J. Nanotechnol. 2022, 13, 653–665, doi:10.3762/bjnano.13.57

• activation function is especially noticeable for the case of a superposition of basic states. We have also shown how dissipation suppresses “quantum” oscillations on the activation function, just as damping suppresses plasma oscillations in classical Josephson systems. The obtained results pave the way for a

Quantitative dynamic force microscopy with inclined tip oscillation

• Philipp Rahe,
• Daniel Heile,
• Reinhard Olbrich and
• Michael Reichling

Beilstein J. Nanotechnol. 2022, 13, 610–619, doi:10.3762/bjnano.13.53

• equations that link the physical interaction parameters force and damping with the measurement observables static deflection qs, oscillation amplitude A, and phase φ as well as the excitation parameters frequency fexc and force Fexc. This theory specifically predicts the distant-dependent frequency shift

• of a viscous damping layer, in-plane dissipation mechanisms have been found to cause systematic changes of the phase shift in amplitude-modulation AFM depending on the cantilever inclination [15]. Furthermore, it has been proposed to use the presence of a lateral component in the tip oscillation path

• whereby the vectorial damping coefficient and the damping coefficient along the oscillation path have been introduced to write the odd force as Force response for the inclined sampling path By reinterpreting the cup and cap averaging functionals as line integrals along the inclined tip sampling path

Approaching microwave photon sensitivity with Al Josephson junctions

• Andrey L. Pankratov,
• Anna V. Gordeeva,
• Leonid S. Revin,
• Dmitry A. Ladeynov,
• Anton A. Yablokov and
• Leonid S. Kuzmin

Beilstein J. Nanotechnol. 2022, 13, 582–589, doi:10.3762/bjnano.13.50

• damping values [48][49]: The used notations are the following: i = Ibias/Ic is the dimensionless bias current with the bias current Ibias and the critical current Ic, is the potential barrier height, γ = IT/Ic is the noise intensity, and IT = 2ekT/ℏ is the fluctuational current which can be calculated as

Electrostatic pull-in application in flexible devices: A review

• Teng Cai,
• Yuming Fang,
• Yingli Fang,
• Ruozhou Li,
• Ying Yu and
• Mingyang Huang

Beilstein J. Nanotechnol. 2022, 13, 390–403, doi:10.3762/bjnano.13.32

• structure of perforated parallel plates supported by four serpentine springs. The elastic coefficient can be significantly reduced by the serpentine meander structure. Also, the capacitance and viscous air damping can be effectively reduced by the perforated structure, thus reducing the pull-in voltage

Nanoscale friction and wear of a polymer coated with graphene

• Robin Vacher and
• Astrid S. de Wijn

Beilstein J. Nanotechnol. 2022, 13, 63–73, doi:10.3762/bjnano.13.4

• particles of the AFM tip. This leads to a fairly small total tip mass. While this is not entirely physical, such a low mass will help speed up the dynamics and damping of the tip and save computation time without compromising the results [32]. We simulate the system with a time step of 1 fs. Substrate

• ensemble. The temperature of the melt at this point is extremely high. To obtain a realistic semicrystalline substrate structure, we cool down the sample using a Nosé–Hoover thermostat with a linearly decreasing temperature, starting at 5000 K down to 220 K with a cooling rate of 75 K/ns. The damping time

• 300 K and a damping time of 0.1 ps. This thermostat is applied only to the bottom quarter of the PVA molecules, and later to the graphene sheet. To prevent the polymer slab from moving as a result of the external forces during deposition of the graphene, indentation, and sliding, the centers of mass

Heating ability of elongated magnetic nanoparticles

• Elizaveta M. Gubanova,
• Nikolai A. Usov and
• Vladimir A. Oleinikov

Beilstein J. Nanotechnol. 2021, 12, 1404–1412, doi:10.3762/bjnano.12.104

• ]: Here kB is the Boltzmann constant, γ is the gyromagnetic ratio, κ is phenomenological damping constant, δαβ is the Kronecker delta, and δ(t) is the delta function. The calculations of the low-frequency hysteresis loops are carried out at room temperature, T = 300 K. Results and Discussion SAR of dilute

Alteration of nanomechanical properties of pancreatic cancer cells through anticancer drug treatment revealed by atomic force microscopy

• Xiaoteng Liang,
• Shuai Liu,
• Xiuchao Wang,
• Dan Xia and
• Qiang Li

Beilstein J. Nanotechnol. 2021, 12, 1372–1379, doi:10.3762/bjnano.12.101

• smaller than that of the three PCCs. This could be caused by the difference of the internal friction and/or vicious damping [26][27] between the normal and the cancer cells. The relative Young’s modulus distributions of different kinds of cells, according to the nanomechanical mapping (Figure 3a–d) and

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

• shape of the cantilever, ρA is the mass per unit length, ccantilever is the linear viscous damping coefficient, and EI is the cantilever flexural rigidity. Dots over variables refer to time derivatives, while primes denote partial derivatives with respect to the position along the cantilever length

• parameter results allow for the calculation of the sample stiffness ksample and the mass per unit length ρA. Next, combining the latter term with the quality factor Q of the first contact mode, the linear viscous cantilever damping is defined as: Remaining system parameters relating to the tip–sample

Irradiation-driven molecular dynamics simulation of the FEBID process for Pt(PF₃)₄

• Alexey Prosvetov,
• Alexey V. Verkhovtsev,
• Gennady Sushko and
• Andrey V. Solov’yov

Beilstein J. Nanotechnol. 2021, 12, 1151–1172, doi:10.3762/bjnano.12.86

• moving in space. In this study a sub-monolayer of Pt(PF3)4 with the size of 20 nm × 20 nm is optimized, adsorbed on a SiO2-H substrate and thermalized at 300 K for 0.1 ns using the Langevin thermostat with a damping time of 0.2 ps. The constructed layer consists of approximately 370 molecules that

Reducing molecular simulation time for AFM images based on super-resolution methods

• Zhipeng Dou,
• Jianqiang Qian,
• Yingzi Li,
• Rui Lin,
• Jianhai Wang,
• Peng Cheng and
• Zeyu Xu

Beilstein J. Nanotechnol. 2021, 12, 775–785, doi:10.3762/bjnano.12.61

• virtual atom is added above the tip apex and they are connected with a spring in the z-direction. The virtual atom is excited by a sinusoidal signal, mimicking the acoustic excitation of AM-AFM. The excited frequency is adjusted by the spring stiffness. A damping force is applied on the tip to ensure the

• correct damping of the tip oscillation. In the simulation, the initial distance between the virtual atom and the sample surface Zc remains unchanged at a suitable distance. Then we employ the raster scanning method to construct the average interplay energy map of the sample surface in a calculation period

The patterning toolbox FIB-o-mat: Exploiting the full potential of focused helium ions for nanofabrication

• Victor Deinhart,
• Lisa-Marie Kern,
• Jan N. Kirchhof,
• Sabrina Juergensen,
• Joris Sturm,
• Enno Krauss,
• Thorsten Feichtner,
• Sviatoslav Kovalchuk,
• Michael Schneider,
• Dieter Engel,
• Bastian Pfau,
• Bert Hecht,
• Kirill I. Bolotin,
• Stephanie Reich and
• Katja Höflich

Beilstein J. Nanotechnol. 2021, 12, 304–318, doi:10.3762/bjnano.12.25

• feature dipole-forbidden eigenmodes [58] with low damping when being excited by the incidence of structured light [59]. First, we focus on comparable tetramer geometries to assess the influence on geometric fidelity and possible ion-beam induced material/substrate modifications on the plasmonic response

Numerical analysis of vibration modes of a qPlus sensor with a long tip

• Kebei Chen,
• Zhenghui Liu,
• Yuchen Xie,
• Chunyu Zhang,
• Gengzhao Xu,
• Wentao Song and
• Ke Xu

Beilstein J. Nanotechnol. 2021, 12, 82–92, doi:10.3762/bjnano.12.7

• . Table 1 summarizes the parameters used, including Young’s modulus, Poisson’s ratio, mass density, and damping coefficients for all materials considered. The values for Torr seal epoxy were chosen as in the papers by Dennis van Vörden et al. [25] and Omur E. Dagdeviren and co-workers [26]. The parameters

• for quartz, gold, and tungsten were taken from the materials library of the simulation software, except for the damping coefficient for quartz, which was chosen based on our experimental results. According to [26], it is also worth noting that (i) due to the comparatively low internal damping

• occurring inside gold and tungsten, we did not assign a damping coefficient to any of these materials to reduce the computational cost, and that (ii) the sensor is oscillating in vacuum. Observation by scanning electron microscope (SEM) Firstly, in this paper, the whole assembly consisting of tuning fork

Application of contact-resonance AFM methods to polymer samples

• Sebastian Friedrich and
• Brunero Cappella

Beilstein J. Nanotechnol. 2020, 11, 1714–1727, doi:10.3762/bjnano.11.154

• –sample system as a vertical spring ignores lateral forces (and related torsion) and damping [8][26]. The models do not represent satisfactorily the complex situation of a CR measurement on a polymer. In other words, different values of γ for different samples “compensate” for the lack of parameters

• structure, tip mass, plastic deformations, viscoelastic behavior, adhesion, lateral forces, and damping increases significantly the number of free parameters, so that the practical use of such complex models is very limited. The dependence of γ on the sample is a severe limitation for measurements on thin

• , adhesion, and damping should be accounted for in models of the system. Unfortunately, especially in case of polymers, this would drastically increase the number of parameters needed for the description of the cantilever–sample system. The inadequacy of simple models for the description of polymer samples