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

• between the channel and a metal contact [29][30]. Indeed, the generation of the Ti4O7 Magnéli phase from TiO2 can require significant power dissipation, lead to material damage to the device as oxygen gas evolves, and, in the case of bipolar devices, require an initial irreversible “electroforming” step

Multiple regimes of operation in bimodal AFM: understanding the energy of cantilever eigenmodes

• Daniel Kiracofe,
• Arvind Raman and
• Dalia Yablon

Beilstein J. Nanotechnol. 2013, 4, 385–393, doi:10.3762/bjnano.4.45

• information about the ratio of the dissipative interaction to the conservative interaction. The lower phase lag in (c) and (d) indicates a lower ratio of dissipative interaction to conservative interaction (i.e., either less dissipation, higher conservative forces, or both), as compared to (a) and (b). It

• obtain the value at 250 kHz) for polypropylene and polyethylene at 250 kHz, respectively. Both materials have a surface energy hysteresis term of 0.06 J/m2 (chosen to approximately match the average energy dissipation in AM-AFM experiments). The same first eigenmode amplitude is used for both simulations

• (i.e., Hertz contact without energy dissipation). The result is shown in Figure 7. In this case there are no discontinuous jumps. There is a point at which the slope of the amplitude and phase curves change, but there is no contrast reversal in either. Also, there is essentially no change in the first

Selective surface modification of lithographic silicon oxide nanostructures by organofunctional silanes

• Thomas Baumgärtel,
• Christian von Borczyskowski and
• Harald Graaf

Beilstein J. Nanotechnol. 2013, 4, 218–226, doi:10.3762/bjnano.4.22

• AFM measurement (water adsorption or the energy dissipation of the AFM tip) should be investigated in detail in further statistical studies. Covalent binding of FITC to silicon oxide nanostructures Once suitable conditions for the controlled silanization of LAO nanostructures had been found

Photoresponse from single upright-standing ZnO nanorods explored by photoconductive AFM

• Igor Beinik,
• Markus Kratzer,
• Astrid Wachauer,
• Lin Wang,
• Yuri P. Piryatinski,
• Gerhard Brauer,
• Xin Yi Chen,
• Yuk Fan Hsu,
• Aleksandra B. Djurišić and
• Christian Teichert

Beilstein J. Nanotechnol. 2013, 4, 208–217, doi:10.3762/bjnano.4.21

• as water and oxygen. Under the applied conditions, the water layer may be several monolayers thick. Once the current rises the initial surface conditions will be changed due to electrochemical processes, electromigration and local power dissipation. One of the major changes will be a reduction of the

• likely caused by contact instabilities, even though the experiments were carried out in a regime where the tip loading force should be sufficient to provide a stable contact. It should also be noted that the current level is in the μA range, which leads to a considerable power dissipation and heating of

• observed transient photocurrent may also be related to the local annealing of oxygen defects due to power-dissipation heating at the nanocontact formed between the ZnO NR and the conductive AFM tip. Schematic drawing of the PC-AFM setup. The sample in the present configuration was illuminated from the top

Bimodal atomic force microscopy driving the higher eigenmode in frequency-modulation mode: Implementation, advantages, disadvantages and comparison to the open-loop case

• Daniel Ebeling and
• Santiago D. Solares

Beilstein J. Nanotechnol. 2013, 4, 198–207, doi:10.3762/bjnano.4.20

• be shown that the frequency shift signal is, at a first approximation, only affected by conservative interactions while the measured drive amplitude is mainly influenced by dissipation [23][24][25]. However, in AM-AFM both measured signals (amplitude and phase shift) depend on both types of

• interactions (conservative and dissipative) [26] (note that the measured frequency shift is also indirectly affected by dissipation in large-amplitude intermittent-contact experiments, in that dissipative forces can limit penetration of the probe tip into the repulsive region of the tip–sample interaction

• experimentally feasible, it represents a promising theoretical limit. The next question concerns the relationship between the frequency shift and the phase contrast, which can be easily answered by using the damped harmonic oscillator model [22]. In the absence of tip–sample dissipation, the phase of the

High-resolution dynamic atomic force microscopy in liquids with different feedback architectures

• John Melcher,
• David Martínez-Martín,
• Miriam Jaafar,
• Julio Gómez-Herrero and
• Arvind Raman

Beilstein J. Nanotechnol. 2013, 4, 153–163, doi:10.3762/bjnano.4.15

• separation regulator in FM actuates z in order to maintain the frequency shift σ according to where K5 and K6 are gain constants, and σsp is the set-point frequency shift. At equilibrium in FM, the topography is purely a reflection of the virial of the interaction and the dissipation is measured in the

• corresponding excitation force signal. The separation regulator in DAM actuates z in order to maintain the excitation force according to where K5 and K6 are gain parameters and Fsp is the force at the set-point. At equilibrium in DAM, the topography is purely a reflection of the dissipation, and the virial is

• higher eigenmodes [36][37]. The present theory does not extend to soft microcantilevers in liquids. However, from prior work, we can expect that the primary difference for soft microcantilevers is that the dissipation reflects the energy lost to higher harmonics [38][39]. Performance metrics for high

Towards 4-dimensional atomic force spectroscopy using the spectral inversion method

• Jeffrey C. Williams and
• Santiago D. Solares

Beilstein J. Nanotechnol. 2013, 4, 87–93, doi:10.3762/bjnano.4.10

• , Figure 7 in [11]) and can compound itself with distortions in the force curve that may emerge in the presence of dissipation, whereby the hysteresis loops in the tip–sample force curve can change shape or shift along the tip-position axis as harmonics are removed from the spectrum (see Figure 5). Even

Interpreting motion and force for narrow-band intermodulation atomic force microscopy

• Daniel Platz,
• Daniel Forchheimer,
• Erik A. Tholén and
• David B. Haviland

Beilstein J. Nanotechnol. 2013, 4, 45–56, doi:10.3762/bjnano.4.5

• , corresponding to a increasingly dissipative tip–surface interaction. However, the maximum dissipation does not coincide with the maximum repulsive conservative force, and the energy dissipation is largest at peak amplitude for piezo extensions between 2 and 6 nm. Another interesting feature of the FI map is the

Characterization and properties of micro- and nanowires of controlled size, composition, and geometry fabricated by electrodeposition and ion-track technology

• Maria Eugenia Toimil-Molares

Beilstein J. Nanotechnol. 2012, 3, 860–883, doi:10.3762/bjnano.3.97

Spring constant of a tuning-fork sensor for dynamic force microscopy

• Dennis van Vörden,
• Manfred Lange,
• Merlin Schmuck,
• Nico Schmidt and
• Rolf Möller

Beilstein J. Nanotechnol. 2012, 3, 809–816, doi:10.3762/bjnano.3.90

• attached to the support. This is due to the area connecting the two prongs, which is deformed during the oscillation. This is not only important for the spring constant but also for the dissipation of the TF. Dynamic measurements have shown that applying glue to that area will reduce the quality factor of

• strength using [31]. Comparison of the different evaluation methods. Acknowledgements Financial support from the Deutsche Forschungsgemeinschaft through SFB616 “‘Energy dissipation at surfaces”’ is gratefully acknowledged. The authors would like to thank D. Utzat for improving the electronics.

Focused electron beam induced deposition: A perspective

• Michael Huth,
• Fabrizio Porrati,
• Christian Schwalb,
• Marcel Winhold,
• Roland Sachser,
• Maja Dukic,
• Jonathan Adams and
• Georg Fantner

Beilstein J. Nanotechnol. 2012, 3, 597–619, doi:10.3762/bjnano.3.70

• bias current. Future research will have to show whether this is the result of local crystallization towards the Pt2Si3-phase caused by the high dissipation levels under large current bias. For details concerning the electronic transport properties of nanogranular FEBID structures the reader is referred

Repulsive bimodal atomic force microscopy on polymers

• Alexander M. Gigler,
• Christian Dietz,
• Maximilian Baumann,
• Nicolás F. Martinez,
• Ricardo García and
• Robert W. Stark

Beilstein J. Nanotechnol. 2012, 3, 456–463, doi:10.3762/bjnano.3.52

• establishing a method to separate attractive and repulsive contributions to the interaction force. To this end, it has to be proven whether such low setpoint ratios lead to stable imaging conditions. Bimodal APD curves may also give further insight into the various modes of energy dissipation because bimodal

Drive-amplitude-modulation atomic force microscopy: From vacuum to liquids

• Miriam Jaafar,
• David Martínez-Martín,
• Mariano Cuenca,
• John Melcher,
• Arvind Raman and
• Julio Gómez-Herrero

Beilstein J. Nanotechnol. 2012, 3, 336–344, doi:10.3762/bjnano.3.38

• environments. Drive-amplutide modulation is a very stable, intuitive and easy to use mode that is free of the feedback instability associated with the noncontact-to-contact transition that occurs in the frequency-modulation mode. Keywords: atomic force microscopy; control systems; dissipation; frequency

• dissipative forces, that subtract energy from the oscillation [16][17]. The dissipation generally grows monotonically [18] as the tip approaches the sample surface (Figure 1b). However, the precise dependence of the dissipation on the tip–sample distance depends on the detailed atomic configuration of the tip

• involved in the experiment [19]. In this work we present a new AFM scanning mode, which we have called “drive amplitude modulation” (DAM-AFM) [20] and which takes advantage of the aformentioned monotonicity of the dissipation to obtain stable images in all environments from vacuum to liquids. Moreover, DAM

Models of the interaction of metal tips with insulating surfaces

• Thomas Trevethan,
• Matthew Watkins and
• Alexander L. Shluger

Beilstein J. Nanotechnol. 2012, 3, 329–335, doi:10.3762/bjnano.3.37

• consisting of strong displacement of an anion out of the surface to bond to the tip apex. This jump of a surface ion to the tip apex will result in hysteresis in the tip–surface force field and atomic-scale dissipation being measured by the NC-AFM instrument [23][24]. For the Cr tip interacting with the NaCl

Graphite, graphene on SiC, and graphene nanoribbons: Calculated images with a numerical FM-AFM

• Fabien Castanié,
• Laurent Nony,
• Sébastien Gauthier and
• Xavier Bouju

Beilstein J. Nanotechnol. 2012, 3, 301–311, doi:10.3762/bjnano.3.34

• , and giving at the end an image representing a dissipation measurement. The second one keeps the resonance frequency shift Δf due to the probe–surface interaction constant, hence providing the topographic image. The complexity of the two entangled loops of the FM-AFM, each with different gain

• as dissipation [66][124][125] and the influence of noise perturbations [126]. Illustration of constant-height and constant-Δf imaging modes in nc-AFM. We consider, as an illustrative situation, the cases of a homogeneous and atomically corrugated surface with a step (a) and a heterogeneous, but still

Wavelet cross-correlation and phase analysis of a free cantilever subjected to band excitation

• Francesco Banfi and
• Gabriele Ferrini

Beilstein J. Nanotechnol. 2012, 3, 294–300, doi:10.3762/bjnano.3.33

• response and the driving signal under reasonable assumptions [15]. In the last few years, the investigation of phase-analysis techniques [16][17] contributed to the understanding of energy-dissipation processes and elastic response in heterogeneous samples, an important topic in biological research, where

Simultaneous current, force and dissipation measurements on the Si(111) 7×7 surface with an optimized qPlus AFM/STM technique

• Zsolt Majzik,
• Martin Setvín,
• Andreas Bettac,
• Albrecht Feltz,
• Vladimír Cháb and
• Pavel Jelínek

Beilstein J. Nanotechnol. 2012, 3, 249–259, doi:10.3762/bjnano.3.28

• interferometric deflection. Keywords: AFM; cross-talk; current; dissipation; force; qPlus; STM; tuning fork; Introduction The invention of scanning probe techniques, in particular scanning tunneling microscopy (STM) [1] and atomic force microscopy (AFM) [2], had a tremendous impact on our understanding of the

• with the modified setup were carried out to prove that the cross-talk has no significant impact on the measured quantities. Simultaneously measured force, tunneling current and dissipation are compared to theoretical predictions [34] and with measurements of the optical interferometric deflection [21

• amplitude leading to the appearance of a “dissipation” signal. This can take both positive and negative values. Finally, special attention has to be paid when the tuning fork is used at higher harmonics or higher flexural modes, because the harmonic modulation of the tunneling current can appear in the

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

• gradient between the oscillating tip and a surface (force-spectroscopy measurements). When nonconservative forces act between the tip apex and the surface the oscillation amplitude is damped. The dissipation is caused by bistabilities in the potential energy surface of the tip–sample system, and the

• –distance curves upon approach and retraction. Furthermore, a second dissipation process was identified through the damping of the oscillation while the molecule on the tip is in contact with the surface. This dissipation process occurs mainly during the retraction of the tip. It reaches a maximum value of

• 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

Theoretical study of the frequency shift in bimodal FM-AFM by fractional calculus

• Elena T. Herruzo and
• Ricardo Garcia

Beilstein J. Nanotechnol. 2012, 3, 198–206, doi:10.3762/bjnano.3.22

• between observables and forces is difficult to deduce. Since the observable quantities in dynamic modes are averaged over many cycles of oscillation (amplitude and phase shift for amplitude modulation AFM (AM-AFM) [20][21], and frequency shift and dissipation for FM-AFM [22][23]), it is not

• and dissipation of the second mode in bimodal FM-AFM. Experimental measurements have shown the ability of bimodal AFM to measure a variety of interactions, from electrostatic to magnetic or mechanical, both in ultrahigh vacuum [36][37][38], air [33][34][39][40][41] and liquids [15][18][19

Molecular-resolution imaging of pentacene on KCl(001)

• Julia L. Neff,
• Jan Götzen,
• Enhui Li,
• Michael Marz and
• Regina Hoffmann-Vogel

Beilstein J. Nanotechnol. 2012, 3, 186–191, doi:10.3762/bjnano.3.20

• the molecules on the surface. Another possibility is that the line defect results from a twinned growth. The line defect also has a profound effect on the energy dissipation (Figure 2b). The dissipated energy per oscillation cycle can be estimated by Ediss ≈ E0(Aexc − Aexc,0)/Aexc,0 with E0 = πkA2/Q

• ’ in Figure 2b) about 250 meV/cycle are additionally dissipated in each unit cell. At the line defect two areas can be distinguished. In one row of unit cells (area B) only the intrinsic dissipation of the cantilever is observed. Whereas, in another row (C) up to 760 meV are additionally dissipated per

• oscillation cycle. The increased energy dissipation could be due to extra uncompensated electrostatic charge that induces currents in the tip in each oscillation cycle. In this case, we would expect to see strong effects from this charge in the topographic image,which we do not observe. Another possibility is

Current-induced forces in mesoscopic systems: A scattering-matrix approach

• Niels Bode,
• Silvia Viola Kusminskiy,
• Reinhold Egger and
• Felix von Oppen

Beilstein J. Nanotechnol. 2012, 3, 144–162, doi:10.3762/bjnano.3.15

• fluctuations of the force operator −d†Λνd in Equation 7. As indicated by the fluctuation–dissipation theorem, the fluctuating force is of the same order in the adiabatic expansion as the velocity-dependent force. Thus, we can evaluate the expression for the correlator Dνν′(X) of the fluctuating force given in

• through In the next section we will see that the A-matrix is essential to express the current-induced dissipation and “Lorentz” forces in Equation 27 and Equation 28. Current-induced forces Mean force: The mean force exerted by the electrons on the oscillator is given by Equation 26. Writing Equation 26

• terms, the symmetric matrix γs, which is responsible for dissipation of the mechanical system into the electronic bath. The manipulations to write the dissipation term as a function of S-matrix quantities are lengthy and the details are given in Supporting Information File 1, Section B. The damping

Substrate-mediated effects in photothermal patterning of alkanethiol self-assembled monolayers with microfocused continuous-wave lasers

• Anja Schröter,
• Mark Kalus and
• Nils Hartmann

Beilstein J. Nanotechnol. 2012, 3, 65–74, doi:10.3762/bjnano.3.8

• nm is feasible. Rapid heat dissipation, though, requires high laser powers. In contrast, patterning of SAMs on Au/glass substrates is strongly affected by the largely distinct heat conduction within the Au film and in the glass support. This results in broad surface temperature profiles. Hence

• certain peak temperature rise is attributed to the largely distinct heat dissipation in the supports, Si versus glass. Au, of course, exhibits a very high thermal conductivity. Thus, with increasing Au layer thickness thermal conduction in Au/glass substrates is more and more affected by heat dissipation

Effect of the tip state during qPlus noncontact atomic force microscopy of Si(100) at 5 K: Probing the probe

• Adam Sweetman,
• Sam Jarvis,
• Rosanna Danza and
• Philip Moriarty

Beilstein J. Nanotechnol. 2012, 3, 25–32, doi:10.3762/bjnano.3.3

• imaging and force spectroscopy of the Si(100) surface at 5 K by qPlus [21] NC-AFM at zero applied bias, and investigate the influence of different apex types on the qualitative image appearance, and quantitative short-range tip–sample force and dissipation. Experimental details We used a commercial low

• ” image, despite looking superficially similar, actually shows a marked reduction in apparent corrugation. In contrast, the “discus-like” image shows a dramatically enhanced corrugation, suggesting (in light of significant dissipation observed during imaging; see Supporting Information File 1) that the

• order as the uncertainties associated with the technique for the long-range fitting. Nonetheless, we are able to state that the force profiles associated with the “inverted” image differ significantly from the “dimer” and “conventional” images, and that the observed dissipation varies strongly between

X-ray spectroscopy characterization of self-assembled monolayers of nitrile-substituted oligo(phenylene ethynylene)s with variable chain length

• Hicham Hamoudi,
• Ping Kao,
• Alexei Nefedov,
• David L. Allara and
• Michael Zharnikov

Beilstein J. Nanotechnol. 2012, 3, 12–24, doi:10.3762/bjnano.3.2

• semiconductor microelectronics devices, although very efficient and compact, are being pushed to their physical limits in terms of further miniaturization with associated issues such as electrical leakage and heat dissipation, and hence this is driving consideration of entirely new types of platforms. One

Direct monitoring of opto-mechanical switching of self-assembled monolayer films containing the azobenzene group

• Einat Tirosh,
• Enrico Benassi,
• Silvio Pipolo,
• Marcel Mayor,
• Michal Valášek,
• Veronica Frydman,
• Stefano Corni and
• Sidney R. Cohen

Beilstein J. Nanotechnol. 2011, 2, 834–844, doi:10.3762/bjnano.2.93

•  8. Mechanical characterization was performed in the AFM by using HarmoniXTM imaging (Bruker, Santa Barbara, CA USA). The HarmoniX AFM technique allows the acquisition of quantitative "images" of mechanical parameters (elastic modulus, adhesion, dissipation) simultaneously with and at the rate of