Modeling viscoelasticity through spring–dashpot models in intermittent-contact atomic force microscopy

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

Beilstein J. Nanotechnol. 2014, 5, 2149–2163, doi:10.3762/bjnano.5.224

• to its original position. Despite the limitations of the Linear Maxwell model, it is able to model dissipation which is evidenced by the presence of a hysteresis loop in the force–distance (FD) curve (see Figure 1c). This dissipation loop arises from the gap between the energy input (energy given by

Dissipation signals due to lateral tip oscillations in FM-AFM

• Michael Klocke and
• Dietrich E. Wolf

Beilstein J. Nanotechnol. 2014, 5, 2048–2057, doi:10.3762/bjnano.5.213

• , the effects that take place are far more complex than having just a single hysteresis loop. Depending on the indentation depth of the tip (or the minimum distance between tip and sample), multiple adhesion hysteresis loops might occur [10]. It can also happen that in some of the cycles, there is no

• adhesion hysteresis loop at all, which leads to complex beating phenomena [11]. Moreover, alternative dissipation effects have been discussed, and it is possible that these effects are additionally at work [12][13][14][15]. In this paper, we propose another dissipation mechanism, which can enhance the

Probing viscoelastic surfaces with bimodal tapping-mode atomic force microscopy: Underlying physics and observables for a standard linear solid model

• Santiago D. Solares

Beilstein J. Nanotechnol. 2014, 5, 1649–1663, doi:10.3762/bjnano.5.176

• repulsive force and the average energy dissipated through the hysteresis loop in the force curve over several cycles. In Figure 4b and Figure 4c the time axis has been normalized by the respective cantilever period. As expected from a viscoelastic system, the amount of surface relaxation (distance between

• the force minima for a given frequency in Figure 4a) decreases with increasing frequency as the hysteresis loop area also decreases (see Figure 4d). Additionally, the peak force increases. This is because at faster time scales the system behavior becomes more elastic and less viscous. This frequency

• = 5 nm and any other parameters indicated in the figures. Effect of the SLS parameter Kinf on tip–sample interactions and cantilever response. (a) First and second mode phase, and second mode amplitude; (b) dissipated energy calculated from the hysteresis loop of the tip–sample force trajectory and

Effects of palladium on the optical and hydrogen sensing characteristics of Pd-doped ZnO nanoparticles

• Anh-Thu Thi Do,
• Hong Thai Giang,
• Thu Thi Do,
• Ngan Quang Pham and
• Giang Truong Ho

Beilstein J. Nanotechnol. 2014, 5, 1261–1267, doi:10.3762/bjnano.5.140

• ][18], which is characterized by the hysteresis loop, and it does not exhibit any limiting adsorption at high relative pressures. The specific BET surface area of the ZnO and Pd/ZnO samples were determined to be 37.5 and 34.32 m2/g, respectively, the calculated BJH pore sizes were 8.7 and 10.6 nm

Nanoporous composites prepared by a combination of SBA-15 with Mg–Al mixed oxides. Water vapor sorption properties

• Amaury Pérez-Verdejo,
• Alvaro Sampieri,
• Heriberto Pfeiffer,
• Mayra Ruiz-Reyes,
• Juana-Deisy Santamaría and
• Geolar Fetter

Beilstein J. Nanotechnol. 2014, 5, 1226–1234, doi:10.3762/bjnano.5.136

• prepared composites and the SBA-15 show H1 hysteresis loops due to the N2 capillary condensation. It also denotes that the pores present a cylindrical form and narrow size distribution (Figure 1B). Calcined Mg–Al hydrotalcite shows a N2 adsorption–desorption isotherm with a wide hysteresis loop (H3 type

Designing magnetic superlattices that are composed of single domain nanomagnets

• Derek M. Forrester,
• Feodor V. Kusmartsev and
• Endre Kovács

Beilstein J. Nanotechnol. 2014, 5, 956–963, doi:10.3762/bjnano.5.109

• coupled systems). An AP phase exists when there are no scissored states. An index (j = 1,..) is applied to signify the number of distinct plateaus that are present in a hysteresis loop, e.g., AF1j. In the AF1 phase there is a change of state from the scissored one into a parallel one. The AF2 phase does

• system shift between metastable states. The magnetic field has to be cycled a number of times to obtain all of the possible Barkhausen jumps. For example, the last hysteresis loop shown will only display the black lines for many cycles. However, for this case of J = −8, further cycles reveal the dashed

Controlled synthesis and tunable properties of ultrathin silica nanotubes through spontaneous polycondensation on polyamine fibrils

• Jian-Jun Yuan,
• Pei-Xin Zhu,
• Daisuke Noda and
• Ren-Hua Jin

Beilstein J. Nanotechnol. 2013, 4, 793–804, doi:10.3762/bjnano.4.90

• consistent with that shown in Figure 1A–C. A remarkably different result is that the silica synthesized at high MS51 concentration of 23.1 wt % showed a significantly decreased BET surface area (244 m2/g, run 6 in Table 1) and a relatively smaller hysteresis loop (Figure 6A) without a peak value in the pore

A facile synthesis of a carbon-encapsulated Fe₃O₄ nanocomposite and its performance as anode in lithium-ion batteries

• Raju Prakash,
• Katharina Fanselau,
• Shuhua Ren,
• Tapan Kumar Mandal,
• Christian Kübel,
• Horst Hahn and
• Maximilian Fichtner

Beilstein J. Nanotechnol. 2013, 4, 699–704, doi:10.3762/bjnano.4.79

• an H3-type hysteresis loop (Figure 3), which indicates a mesoporous (pore width < 50 nm) nature of the material [21]. In addition, a sharp increase of the adsorbed gas at very low relative-pressures suggesting the presence of micropores (pore width < 2 nm). The micro- and mesoporous volumes were

Characterization of electroforming-free titanium dioxide memristors

• John Paul Strachan,
• J. Joshua Yang,
• L. A. Montoro,
• C. A. Ospina,
• A. J. Ramirez,
• A. L. D. Kilcoyne,
• Gilberto Medeiros-Ribeiro and
• R. Stanley Williams

Beilstein J. Nanotechnol. 2013, 4, 467–473, doi:10.3762/bjnano.4.55

• dramatically reduced microphysical changes after electrical operation. Keywords: electron microscopy; memristor; resistance switching; transition-metal oxide; X-ray spectroscopy; Introduction A memristor is a passive electronic element that displays a pinched hysteresis loop in its current–voltage

Highly ordered ultralong magnetic nanowires wrapped in stacked graphene layers

• Abdel-Aziz El Mel,
• Jean-Luc Duvail,
• Eric Gautron,
• Wei Xu,
• Chang-Hwan Choi,
• Benoit Angleraud,
• Agnès Granier and
• Pierre-Yves Tessier

Beilstein J. Nanotechnol. 2012, 3, 846–851, doi:10.3762/bjnano.3.95

• consequence, no square hysteresis loop, as measured for single-domain and isolated nanowires [3], is expected here, and complex magnetic configurations can take place. Moreover, by comparing the coercive fields measured before and after the post-annealing procedure we can conclude that they are reduced after

Tuning the properties of magnetic thin films by interaction with periodic nanostructures

• Ulf Wiedwald,
• Felix Haering,
• Stefan Nau,
• Carsten Schulze,
• Herbert Schletter,
• Denys Makarov,
• Alfred Plettl,
• Karsten Kuepper,
• Manfred Albrecht,
• Johannes Boneberg and
• Paul Ziemann

Beilstein J. Nanotechnol. 2012, 3, 831–842, doi:10.3762/bjnano.3.93

• that the MFM-extracted film hysteresis loop is similar to the hysteresis measured by integral techniques such as MOKE. Indeed, this has been demonstrated in reference [25]. Magnetization reversal in arrays of spherical gold particles capped with Co/Pt multilayers An alternative approach towards

The memory effect of nanoscale memristors investigated by conducting scanning probe microscopy methods

• César Moreno,
• Carmen Munuera,
• Xavier Obradors and
• Carmen Ocal

Beilstein J. Nanotechnol. 2012, 3, 722–730, doi:10.3762/bjnano.3.82

• are involved, as already observed in other thin-oxide-based memristor systems [4]. The fundamental memristive system theory states that the observation of a pinched current-versus-voltage hysteresis loop measured from an experimental two-terminal device, when driven by a dc and/or sinusoidal signal of

A measurement of the hysteresis loop in force-spectroscopy curves using a tuning-fork atomic force microscope

• Manfred Lange,
• Dennis van Vörden and
• Rolf Möller

Beilstein J. Nanotechnol. 2012, 3, 207–212, doi:10.3762/bjnano.3.23

• process can be understood as a hysteresis of forces between approach and retraction of the tip. In this paper, we present the direct measurement of the whole hysteresis loop in force-spectroscopy curves at 77 K on the PTCDA/Ag/Si(111) √3 × √3 surface by means of a tuning-fork-based NC-AFM with an

• oscillation amplitude smaller than the distance range of the hysteresis loop. The hysteresis effect is caused by the making and breaking of a bond between PTCDA molecules on the surface and a PTCDA molecule at the tip. The corresponding energy loss was determined to be 0.57 eV by evaluation of the force

• about 0.22 eV/cycle. Keywords: atomic force microscopy; energy dissipation; force spectroscopy; hysteresis loop; PTCDA/Ag/Si(111) √3 × √3; Introduction Noncontact atomic force microscopy (NC-AFM) is a powerful tool for the study of surface properties. The invention of the frequency-modulation mode (FM

Mechanical characterization of carbon nanomembranes from self-assembled monolayers

• Xianghui Zhang,
• André Beyer and
• Armin Gölzhäuser

Beilstein J. Nanotechnol. 2011, 2, 826–833, doi:10.3762/bjnano.2.92

• values of ~0.65%, ~1.2% and ~1.7%. The hysteresis loop becomes more and more pronounced with the increase in the maximum tensile strain of each cycle. Hysteresis is one major characteristic of viscoelasticity and is associated with the energy that is dissipated as heat in the loading cycles. The specific

Nanoscaled alloy formation from self-assembled elemental Co nanoparticles on top of Pt films

• Luyang Han,
• Ulf Wiedwald,
• Johannes Biskupek,
• Kai Fauth,
• Ute Kaiser and
• Paul Ziemann

Beilstein J. Nanotechnol. 2011, 2, 473–485, doi:10.3762/bjnano.2.51

• (TA = 250 °C) a narrow hysteresis loop was observed with a coercive field of µ0HC = 27 mT on Pt(100) films, while no clear opening was detected for Co NPs on Pt(111), within the experimental uncertainties. The largest difference of coercive fields was obtained after annealing in the interval TA = 300

• additionally confirms the lateral spread of Co atoms. Additional in-plane hysteresis loops were measured by SQUID magnetometry for 7 nm Co NPs on Pt(111) films after different annealing steps. Note that each hysteresis loop was measured on a separate sample to exclude any effect of the thin SiO cover layer

Structural and magnetic properties of ternary Fe_1–xMn_xPt nanoalloys from first principles

• Markus E. Gruner and
• Peter Entel

Beilstein J. Nanotechnol. 2011, 2, 162–172, doi:10.3762/bjnano.2.20

• film setup. Using a vibrating sample magnetometer for saturation magnetization and hysteresis loop and X-ray magnetic circular dichroism (XMCD) to obtain the element resolved orientation of the moments, the authors observed a linear decrease of the average magnetization with increasing Mn-content

Pore structure and surface area of silica SBA-15: influence of washing and scale-up

• Jörg P. Thielemann,
• Frank Girgsdies,
• Robert Schlögl and
• Christian Hess

Beilstein J. Nanotechnol. 2011, 2, 110–118, doi:10.3762/bjnano.2.13

• solvent shows a significantly changed shape of the isotherm as evidenced by the bulge in the desorption branch at p/p0 = 0.45 as well as by a reduced surface area compared to sample 2B. The closure of the hysteresis loop at p/p0 values between 0.4 and 0.45 for sample 2C can be explained by the tensile

• hemispherical meniscus collapses and the pores are immediately emptied. This also leads to the observed forced closure of the hysteresis loop as pores with smaller diameter do not show a hysteresis [28]. As a result there is a typical sharp peak at 50 Å in the pore size distribution (Figure 6), which can be

• pores of the prepared SBA-15 materials exhibit an average diameter of 70 Å. If part of those pores is narrowed to approximately 50 Å or lower, evaporation is delayed [25][26][27]. As a result the tensile strength effect is observed at p/p0 = 0.45 leading to a forced closure of the hysteresis loop. Its

Ultrafine metallic Fe nanoparticles: synthesis, structure and magnetism

• Olivier Margeat,
• Marc Respaud,
• Catherine Amiens,
• Pierre Lecante and
• Bruno Chaudret

Beilstein J. Nanotechnol. 2010, 1, 108–118, doi:10.3762/bjnano.1.13

• measured under µoH = 1 mT. Inset shows the extracted temperature dependence of MS. AC susceptibility measured for various frequencies (symbols) and their fits (solid lines). Hysteresis loop measured at 2 K. Inset: enlargement near zero field showing the coercive field. Magnetization curves in the

Magnetic coupling mechanisms in particle/thin film composite systems

• Giovanni A. Badini Confalonieri,
• Philipp Szary,
• Durgamadhab Mishra,
• Maria J. Benitez,
• Mathias Feyen,
• An Hui Lu,
• Leonardo Agudo,
• Gunther Eggeler,
• Oleg Petracic and
• Hartmut Zabel

Beilstein J. Nanotechnol. 2010, 1, 101–107, doi:10.3762/bjnano.1.12

• increase of the coercivity and in a change of the shape of the hysteresis loop. In addition, it should be noted that, while the hysteresis loop for the NP monolayer is symmetric, the composite systems show a significant bias. It is important to note that the bias is only observed when the sample is field

• cooled, implying that its origin should be ascribed to an antiferromagnetic/ferromagnetic (AF/FM) coupling [31][32][33][34][35]. The magnetic exchange interaction between an AF and an FM layer can usually be observed as a horizontal shift of the magnetic hysteresis loop, when cooling the material from a

• the coupling between the NPs and the Co layer. A shift of the hysteresis loop at low temperatures indicates an AF/FM exchange bias effect in the composite system, which is likely due to the formation of a CoO layer at the interface. The single NP layer exhibits a stretched blocking temperature

Review and outlook: from single nanoparticles to self-assembled monolayers and granular GMR sensors

• Alexander Weddemann,
• Inga Ennen,
• Anna Regtmeier,
• Camelia Albon,
• Annalena Wolff,
• Katrin Eckstädt,
• Nadine Mill,
• Michael K.-H. Peter,
• Jochen Mattay,
• Carolin Plattner,
• Norbert Sewald and
• Andreas Hütten

Beilstein J. Nanotechnol. 2010, 1, 75–93, doi:10.3762/bjnano.1.10

• significance of dipolar coupling increases. A manifestation of this type of interaction is the induced hysteresis in the detection signal. The coercive field of the ΔTMR-hysteresis loop coincides with the coercive field measured by an alternating gradient magnetometer (AGM). Once a second critical value is

Preparation and characterization of supported magnetic nanoparticles prepared by reverse micelles

• Ulf Wiedwald,
• Luyang Han,
• Johannes Biskupek,
• Ute Kaiser and
• Paul Ziemann

Beilstein J. Nanotechnol. 2010, 1, 24–47, doi:10.3762/bjnano.1.5

• etching (details are given in section 1.4) led to Co NPs with an average particle height of 8 ± 1 nm (measured by AFM) with an interparticle distance D ≈ 60 nm (see inset of Figure 10 (b)). The measured hysteresis loop showed a sample saturation moment, remanent magnetization and a coercive field of MS