5 article(s) from Stemmer, Andreas
Figure 1: A modulation of the tip–sample bias Uts leads to a response in the frequency shift Δf. The time-res...
Figure 2: Design and operation of the time-domain KFM controller. (a) Underlying system model. (b) Measuremen...
Figure 3: Open-loop TD-KFM of a few-layer graphene flake. (a) Topography, (b) estimated topography-induced fr...
Figure 4: Comparison of standard single-scan FM-KFM and closed-loop TD-KFM of two overlapping graphene flakes...
Figure 5: (a) Cross sections of the topography along the sections indicated in Figure 4 for single-scan FM-KFM (feedb...
Figure 1: Scanning thermal measurements of the InAs nanowire. (a) Setup for SThM measurements. (b) Topography...
Figure 2: Surface potential measurements of the InAs nanowire. (a) Setup for KFM measurements. (b) Topography...
Figure 3: Electrical characteristics extracted from KFM measurements. (a) Two-terminal I–V characteristics of...
Figure 4: Temperature profiles along the nanowire simulated from its electrical characteristics. The nanowire...
Figure 1: (a) Current–voltage relation of 20 µm × 10 µm gold nanoparticle monolayer before (black) and after ...
Figure 2: SEM images of (a) a pristine gold nanoparticle monolayer, (b) after EtOH immersion and (c) after TH...
Figure 3: Evolution of gold nanoparticle monolayers upon solvent immersion measured by SEM and SAXS. (a) Radi...
Figure 4: The change in lattice constant extracted from the radial power spectral density of SEM images taken...
Figure 5: Influence of solvent alone and of solvent containing conjugated ligands on device conductance. (a) ...
Figure 1: Experimental setup. a) Feedback scheme. The dashed parts enable the slow-drift compensation. Also s...
Figure 2: a) Evolution of resonance frequency shift (black), excitation (red), and dew point (blue) over a du...
Figure 3: Application of the slow feedback control. a) Evolution of frequency shift Δf (black), frequency shi...
Figure 4: Smoothed frequency-shift (black) versus distance curve on HOPG and tip–sample force Fts (red) calcu...
Figure 5: Topography (a) of HOPG after rinsing with Milli-Q water and height profiles (b) along the lines ind...
Figure 6: High-resolution detuning image of HOPG in quasi-constant height mode. Inset: 3-fold symmetrised dri...
Figure 1: Contributions of apex, cone, and cantilever to the first (AM, left) and second (FM, right) order ca...
Figure 2: a) Sideband amplitude (blue) and phase (red) relative to the carrier oscillation measured during a ...
Figure 3: In-phase (red) and quadrature (blue) sideband amplitudes, normalised to the carrier oscillation amp...
Figure 4:
Modulation indices of the sidebands at ωm (a) and 2ωm (b) against for different modulation amplitu...
Figure 5: Block diagram of a Kelvin controller based on a) a proportional–integral–differential (PID) control...
Figure 6: Closed-loop response of the Kelvin observer (black) and a proportional-integral controller (red) to...
Figure 7: Normalised closed-loop bandwidth (−3 dB) of the steady-state Kelvin observer as a function of the n...
Figure 8: Schematic of the modified KFM setup. For topography feedback, the cantilever is excited at a consta...
Figure 9: a) Topography, b) tip–sample capacitance gradient, C'', and c) local contact potential difference, U...
Figure 10: a), b) Kelvin and c), d) error signal of an InAs nanowire similar to the device shown in Figure 9, measured...
Figure 11: One-dimensional power spectral densities of the error signals in Figure 10c,d. Integral feedback works well a...