scholarly journals Impact of electrostatic forces in contact-mode scanning force microscopy

2010 ◽  
Vol 81 (9) ◽  
Author(s):  
F. Johann ◽  
Á. Hoffmann ◽  
E. Soergel
Keyword(s):  
Scanning Force Microscopy ◽  
Electrostatic Forces ◽  
Contact Mode ◽  
Force Microscopy ◽  
Scanning Force

Scanning Force Microscopy Study of Ultrathin Films of Nickel-Phthalocyanine on Graphite

1998 ◽  
Vol 05 (01) ◽  
pp. 433-436 ◽  
Author(s):  
S. Santucci ◽  
S. Di Nardo ◽  
L. Lozzi ◽  
L. Ottaviano ◽  
M. Passacantando ◽  
...  
Keyword(s):  
Pyrolytic Graphite ◽  
Scanning Force Microscopy ◽  
Microscopy Study ◽  
Ex Situ ◽  
Contact Mode ◽  
Force Microscopy ◽  
Nickel Phthalocyanine ◽  
Atomic Force ◽  
Scanning Force

Small amounts of purified nickel-phthalocyanine (Ni-PC) have been deposited at room temperature in ultrahigh vacuum onto highly oriented pyrolytic graphite, and studied "in situ" and "ex situ" (in air) with two different atomic force microscopes. The measurements have been taken on samples as prepared either subsequently annealed at 300°C. The growth mode is not uniform; the PC molecules coalesce into small submicrometric crystallites in the critical size range where the transition from the α to the β crystalline phase of phthalocyanines takes place. We show images of both α-like and β-like crystallites. A contact mode AFM image of an α-like crystallite showing intramolecular resolution is also presented.

Local Electromechanical Properties and Grain Size Effects in Ferroelectric Relaxors Studied by Scanning Piezoelectric Microscopy

2002 ◽  
Vol 748 ◽  
Author(s):  
A. L. Kholkin ◽  
V. V. Shvartsman ◽  
M. Woitas ◽  
A. Safari
Keyword(s):  
Grain Size ◽  
Hysteresis Loops ◽  
Scanning Force Microscopy ◽  
Bias Field ◽  
Electromechanical Properties ◽  
Contact Mode ◽  
Force Microscopy ◽  
Ferroelectric Relaxors ◽  
Scanning Force ◽  
Pt Films

ABSTRACTThe local electromechanical properties of relaxor 0.9Pb(Mg1/3Nb2/3)O3-0.1PbTiO3 (PMN-PT) films are investigated by Scanning Force Microscopy (SFM) in a piezoelectric contact mode. The domain contrast is observed only in some grains (∼20 % of the entire surface), which showed clear ferroelectric behavior. Thus on the microscopic level the material behaves as a composite with ferroelectric regions embedded in the non-polar matrix. This was attributed to the relaxor-to-ferroelectric phase transition induced by the internal bias field. The local hysteresis loops are found to depend on the size of the grains. A distinct correlation between the values of the effective piezoelectric coefficients, deffi and the size of the respective grains is observed. Small grains exhibit slim piezoelectric hysteresis loops with low remanent deff while relatively strong piezoelectric activity is characteristic of larger grains. In addition, large grains exhibit longer relaxation time after poling with an effective time constant increasing with the grain size. The nature of size effect is discussed taking in terms of dynamics of nanopolar clusters and SFM instrumentation.

Characterization of Pzt Films by Scanning Force Microscopy (SFM)

1996 ◽  
Vol 433 ◽  
Author(s):  
Genaro Zavala ◽  
Susan E. Trolier-McKinstry ◽  
Janos H. Fendler
Keyword(s):  
Dielectric Constant ◽  
Lead Zirconate Titanate ◽  
Second Harmonic ◽  
Polarization State ◽  
Scanning Force Microscopy ◽  
Signal Frequency ◽  
Contact Mode ◽  
Force Microscopy ◽  
Pzt Films ◽  
Scanning Force

AbstractScanning Force Microscopy (SFM) has been used for the determination of friction, phase transformation, piezoelectric behavior (contact mode), polarization state and dielectric constant (non contact mode) in several nanometer regions of Lead Zirconate Titanate (PZT) films. The use of the SFM tip, in the contact mode, to polarize different nanoregions of the film and to apply an oscillating field thereon, led to effective piezoelectric coefficients and piezoelectric loops. In the non-contact mode, application of an ac signal (frequency ω) to the tip-electrode system produced an oscillation of the tip at ω (fundamental or first harmonic) and 2ω (second harmonic). The signals ω and 2ω were related to the state of polarization and the dielectric constant of the film. Analysis of the combined contact, non-contact and friction force microscopic data have provided considerable insight into the piezoelectricity and polarization in the nanodomains.

Scanned tip measurement of deep vertical facets on a flat surface: Measuring roughness on gaas laser waveguide mirrors

1993 ◽  
Vol 51 ◽  
pp. 532-533
Author(s):  
Chang Shen ◽  
Phil Fraundorf ◽  
Robert W. Harrick
Keyword(s):  
Integrated Circuits ◽  
Flat Surface ◽  
Scanning Force Microscopy ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Force Microscopy ◽  
Optoelectronic Integrated Circuits ◽  
Laser Waveguide ◽  
Scanning Force ◽  
Gaas Laser

Monolithic integration of optoelectronic integrated circuits (OEIC) requires high quantity etched laser facets which prevent the developing of more-highly-integrated OEIC's. The causes of facet roughness are not well understood, and improvement of facet quality is hampered by the difficulty in measuring the surface roughness. There are several approaches to examining facet roughness qualitatively, such as scanning force microscopy (SFM), scanning tunneling microscopy (STM) and scanning electron microscopy (SEM). The challenge here is to allow more straightforward monitoring of deep vertical etched facets, without the need to cleave out test samples. In this presentation, we show air based STM and SFM images of vertical dry-etched laser facets, and discuss the image acquisition and roughness measurement processes. Our technique does not require precision cleaving. We use a traditional tip instead of the T shape tip used elsewhere to preventing “shower curtain” profiling of the sidewall. We tilt the sample about 30 to 50 degrees to avoid the curtain effect.

Log-log scale roughness spectroscopy of surfaces

1993 ◽  
Vol 51 ◽  
pp. 224-225
Author(s):  
P. Fraundorf ◽  
B. Armbruster
Keyword(s):  
Power Spectrum ◽  
Autocorrelation Function ◽  
Power Spectra ◽  
Scanning Force Microscopy ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Force Microscopy ◽  
Scanning Force ◽  
Lateral Structure ◽  
Scale Roughness

Optical interferometry, confocal light microscopy, stereopair scanning electron microscopy, scanning tunneling microscopy, and scanning force microscopy, can produce topographic images of surfaces on size scales reaching from centimeters to Angstroms. Second moment (height variance) statistics of surface topography can be very helpful in quantifying “visually suggested” differences from one surface to the next. The two most common methods for displaying this information are the Fourier power spectrum and its direct space transform, the autocorrelation function or interferogram. Unfortunately, for a surface exhibiting lateral structure over several orders of magnitude in size, both the power spectrum and the autocorrelation function will find most of the information they contain pressed into the plot’s origin. This suggests that we plot power in units of LOG(frequency)≡-LOG(period), but rather than add this logarithmic constraint as another element of abstraction to the analysis of power spectra, we further recommend a shift in paradigm.

Anisotropy of Nanoindentation – a tool for the determination of nanocrystal orientation ?

2003 ◽  
Vol 779 ◽  
Author(s):  
David Christopher ◽  
Steven Kenny ◽  
Roger Smith ◽  
Asta Richter ◽  
Bodo Wolf ◽  
...  
Keyword(s):  
Crystal Surface ◽  
Scanning Force Microscopy ◽  
Depth Range ◽  
Dislocation Loops ◽  
Force Microscopy ◽  
Pile Up ◽  
Out Of Plane ◽  
Scanning Force ◽  
Dynamics Simulations

AbstractThe pile up patterns arising in nanoindentation are shown to be indicative of the sample crystal symmetry. To explain and interpret these patterns, complementary molecular dynamics simulations and experiments have been performed to determine the atomistic mechanisms of the nanoindentation process in single crystal Fe{110}. The simulations show that dislocation loops start from the tip and end on the crystal surface propagating outwards along the four in-plane <111> directions. These loops carry material away from the indenter and form bumps on the surface along these directions separated from the piled-up material around the indenter hole. Atoms also move in the two out-of-plane <111> directions causing propagation of subsurface defects and pile-up around the hole. This finding is confirmed by scanning force microscopy mapping of the imprint, the piling-up pattern proving a suitable indicator of the surface crystallography. Experimental force-depth curves over the depth range of a few nanometers do not appear smooth and show distinct pop-ins. On the sub-nanometer scale these pop-ins are also visible in the simulation curves and occur as a result of the initiation of the dislocation loops from the tip.

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