Atomic Force Microscopy Of Micron Size Silicalite Crystals

1991 ◽  
Vol 233 ◽  
Author(s):  
P. Rasch ◽  
W. M. Heckl ◽  
H. W. Deckman ◽  
W. Häberle
Keyword(s):  
Perfect Crystal ◽  
Periodic Pattern ◽  
Crystal Surfaces ◽  
Force Microscopy ◽  
Atomic Force ◽  
Micron Size ◽  
Unit Cells ◽  
High Resolution Images ◽  
Long Range Ordering ◽  
Surface Crystallography

ABSTRACTWe have imaged micron sized silicalite crystals with an atomic force microscope (AFM). High resolution images taken in the repulsive mode show a periodic pattern that locally has a symmetry and periodicity which can be mapped onto the expected image looking along the [010] direction. Extra spots, however, appear in the image in regions which should correspond to channels exposed at the surface. These extra spots are attributed to multiple tip effects which should not affect the ability to detect long range ordering. On a scale length of ˜ 3 – 5 unit cells, the ordering in images deviates from that expected for a perfect crystal. This may be due to imperfections in the ordering at crystal surfaces. One other important aspect of the surface crystallography is revealed in low resolution scans where definite steps / grooves in the exposed surface are seen. The results are discussed in terms of the potential of AFM as a probe of surface crystallography.

High-resolution transmission electron microscopic investigations of molybdenum thin films on faceted α-Al2O3

2005 ◽  
Vol 38 (2) ◽  
pp. 260-265 ◽  
Author(s):  
Leonore Wiehl ◽  
Jens Oster ◽  
Michael Huth
Keyword(s):  
High Resolution ◽  
Three Dimensional ◽  
Epitaxial Relationship ◽  
Electron Microscopic ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
High Resolution Images ◽  
Α Al2o3 ◽  
Relationship Of

Epitaxially grown Mo films on a faceted corundum (α-Al2O3)mplane were investigated by transmission electron microscopy. Low- and high-resolution images were taken from a cross-section specimen cut perpendicular to the facets. It was possible to identify unambiguously the crystallographic orientation of these facets and explain the considerable deviation (∼10°) of the experimental interfacet angle, as measured with atomic force microscopy (AFM), from the expected value. For the first time, proof is given for a smooth \{10\bar{1}1\} facet and a curvy facet with orientation near to \{10\bar{1}\bar{2}\}. Moreover, the three-dimensional epitaxial relationship of an Mo film on a faceted corundummsurface was determined.

scholarly journals LIPSS Structures Induced on Graphene-Polystyrene Composite

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3460 ◽  
Author(s):  
Dominik Fajstavr ◽  
Klára Neznalová ◽  
Václav Švorčík ◽  
Petr Slepička
Keyword(s):  
Chemical Properties ◽  
Laser Pulses ◽  
Periodic Pattern ◽  
Krypton Fluoride ◽  
Periodic Surface ◽  
Laser Modification ◽  
Force Microscopy ◽  
Periodic Surface Structure ◽  
Atomic Force ◽  
Physico Chemical

A laser induced periodic surface structure (LIPSS) on graphene doped polystyrene was prepared by the means of a krypton fluoride (KrF) laser with the wavelength of 248 nm and precisely desired physico-chemical properties were obtained for the structure. Surface morphology after laser modification of polystyrene (PS) doped with graphene nanoplatelets (GNP) was studied. Laser fluence values of modifying laser light varied between 0–40 mJ·cm−2 and were used on polymeric PS substrates doped with 10, 20, 30, and 40 wt. % of GNP. GNP were incorporated into PS substrate with the solvent casting method and further laser modification was achieved with the same amount of laser pulses of 6000. Formed nanostructures with a periodic pattern were examined by atomic force microscopy (AFM). The morphology was also studied with scanning electron microscopy SEM. Laser irradiation resulted in changes of chemical composition on the PS surface, such as growth of oxygen concentration. This was confirmed with energy-dispersive X-ray spectroscopy (EDS).

Surface morphology of as grown and annealed bulk GaN crystals

1996 ◽  
Vol 1 ◽  
Author(s):  
G. Nowak ◽  
S. Krukowski ◽  
I. Grzegory ◽  
S. Porowski ◽  
Jacek M. Baranowski ◽  
...  
Keyword(s):  
Surface Morphology ◽  
Flat Surface ◽  
Hydrogen Atmosphere ◽  
The Other ◽  
Crystal Surfaces ◽  
Force Microscopy ◽  
Atomic Force ◽  
Flat Side ◽  
Bulk Gan ◽  
Atomically Flat

GaN single crystals have been grown from Ga solution. The crystals grow in the form of platelets with their basal plane perpendicular to the c-axis. The two opposite crystal surfaces are not equivalent since one is N- and the other Ga-terminated. Atomic force microscopy has been applied to study surface morphology on both surfaces. It was found that one side is atomically flat. The other side consists of pyramid-like structures about 25 nm in size.The influence of annealing in an NH3+H2 atmosphere in the temperature range from 600°C to 900°C was investigated. Depending on crystal face the results were drastically different. It was found that on the rough side, annealing yields an atomically flat surface with terraces of monolayer height. The size of the terraces depends on the temperature of the annealing. On the originally flat side the surface becomes rougher after annealing. The transformation of surface morphology begins at temperatures below 700°C. Preliminary results of annealing in a hydrogen atmosphere are also reported. These findings are crucial for the understanding and development of GaN homoepitaxy.

Preparation of Giant Unilamellar Vesicles and Solid Supported Bilayer from Large Unilamellar Vesicles: Model Biological Membranes

2017 ◽  
Vol 32 (3-4) ◽  
pp. 85 ◽  
Author(s):  
Amrita Basu ◽  
Pabitra Maity ◽  
Prasanta Karmakar ◽  
Sanat Karmakar
Keyword(s):  
Chemical Properties ◽  
Giant Unilamellar Vesicles ◽  
Unilamellar Vesicles ◽  
Force Microscopy ◽  
Atomic Force ◽  
Large Unilamellar Vesicles ◽  
Physico Chemical ◽  
Micron Size ◽  
Planar Membranes ◽  
Extrusion Method

Giant Unilamellar Vesicles (GUV) and supported planar membranes are excellent model biological systems for studying the structure and functions of membranes. We have prepared GUV from Large Unilamellar Vesicles (LUV) using electroformation and Supported planar Lipid Bilayer (SLB) by vesicle fusion method. LUV was prepared using an extrusion method and was characterized using Dynamic Light Scattering (DLS) and zeta potential measurements. The techniques for obtaining GUV as well as SLB from LUV have been demonstrated. We have directly observed the formation of GUV under phase contrast microscopy. This study will provide some insights into the physico-chemical properties of both nano and micron size vesicles. We believe that this method could be extremely useful for reconstituting various bio-molecules in GUV. We have presented one example where an antimicrobial peptide NK-2 was reconstituted in GUV prepared from LUV. SLB formation was monitored and characterized using Atomic Force Microscopy (AFM).

scholarly journals Chemical Resolution at Ionic Crystal Surfaces Using Dynamic Atomic Force Microscopy with Metallic Tips

2011 ◽  
Vol 106 (21) ◽  
Author(s):  
G. Teobaldi ◽  
K. Lämmle ◽  
T. Trevethan ◽  
M. Watkins ◽  
A. Schwarz ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Ionic Crystal ◽  
Crystal Surfaces ◽  
Force Microscopy ◽  
Atomic Force ◽  
Chemical Resolution

scholarly journals Dipole-driven self-organization of zwitterionic molecules on alkali halide surfaces

2012 ◽  
Vol 3 ◽  
pp. 285-293 ◽  
Author(s):  
Laurent Nony ◽  
Franck Bocquet ◽  
Franck Para ◽  
Frédéric Chérioux ◽  
Eric Duverger ◽  
...  
Keyword(s):  
Substrate Surface ◽  
Crystal Surfaces ◽  
High Coverage ◽  
Force Microscopy ◽  
Atomic Force ◽  
Defect Sites ◽  
Low Coverage ◽  
Charged Ions ◽  
Oppositely Charged ◽  
Step Edges

We investigated the adsorption of 4-methoxy-4′-(3-sulfonatopropyl)stilbazolium (MSPS) on different ionic (001) crystal surfaces by means of noncontact atomic force microscopy. MSPS is a zwitterionic molecule with a strong electric dipole moment. When deposited onto the substrates at room temperature, MSPS diffuses to step edges and defect sites and forms disordered assemblies of molecules. Subsequent annealing induces two different processes: First, at high coverage, the molecules assemble into a well-organized quadratic lattice, which is perfectly aligned with the <110> directions of the substrate surface (i.e., rows of equal charges) and which produces a Moiré pattern due to coincidences with the substrate lattice constant. Second, at low coverage, we observe step edges decorated with MSPS molecules that run along the <110> direction. These polar steps most probably minimize the surface energy as they counterbalance the molecular dipole by presenting oppositely charged ions on the rearranged step edge.

scholarly journals Thickness-Dependent Piezoelectric Property from Quasi-Two-Dimensional Zinc Oxide Nanosheets with Unit Cell Resolution

Research ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Corey Carlos ◽  
Yizhan Wang ◽  
Jingyu Wang ◽  
Jun Li ◽  
Xudong Wang
Keyword(s):  
Zinc Oxide ◽  
Piezoelectric Property ◽  
Electrostatic Interactions ◽  
Electromechanical Coupling ◽  
Unit Cell ◽  
Force Microscopy ◽  
Atomic Force ◽  
Unit Cells ◽  
Quantitative Understanding ◽  
Zinc Oxide Nanosheets

A quantitative understanding of the nanoscale piezoelectric property will unlock many application potentials of the electromechanical coupling phenomenon under quantum confinement. In this work, we present an atomic force microscopy- (AFM-) based approach to the quantification of the nanometer-scale piezoelectric property from single-crystalline zinc oxide nanosheets (NSs) with thicknesses ranging from 1 to 4 nm. By identifying the appropriate driving potential, we minimized the influences from electrostatic interactions and tip-sample coupling, and extrapolated the thickness-dependent piezoelectric coefficient (d33). By averaging the measured d33 from NSs with the same number of unit cells in thickness, an intriguing tri-unit-cell relationship was observed. From NSs with 3n unit cell thickness (n=1, 2, 3), a bulk-like d33 at a value of ~9 pm/V was obtained, whereas NSs with other thickness showed a ~30% higher d33 of ~12 pm/V. Quantification of d33 as a function of ZnO unit cell numbers offers a new experimental discovery toward nanoscale piezoelectricity from nonlayered materials that are piezoelectric in bulk.

scholarly journals Tapping Mode Atomic Force Microscopy (TMAFM) of Some Multi-Component Polymers

2013 ◽  
Vol 29 ◽  
pp. 96-103
Author(s):  
Rameshwar Adhikari
Keyword(s):  
Atomic Force Microscopy ◽  
Block Copolymers ◽  
Chemical Society ◽  
Phase Imaging ◽  
Force Microscopy ◽  
Molecular Arrangement ◽  
Atomic Force ◽  
Unit Cells ◽  
Potential Applications ◽  
Nanoscale Morphology

Atomic force microscopy (AFM) has been used frequently in polymer research in particular for imaging topography and phase morphology of multi-component polymers. In this work, we demonstrate the potential applications of the AFM in the study of morphology of multi-component polymers taking examples of some technically important semicrystalline polymers, blends and nanostructured block copolymers. The morphology of semicrystalline morphology could be determined ranging from molecular arrangement in the unit cells to the lamellar structure to the macroscopic morphology showing the spherulites of the polymers. Nanoscale morphology of block copolymers, nanocomposites and blends could be easily accessed by the aping mode AFM (TMAFM) phase imaging technique. It has been demonstrated that TMAFM phase imaging can be successfully utilized as a routine tool for the investigation of nanoscale morphology of the heterogeneous polymers.DOI: http://dx.doi.org/10.3126/jncs.v29i0.9258Journal of Nepal Chemical Society Vol. 29, 2012 Page:  96-103 Uploaded date: 12/5/2013 

Use of In Situ Atomic Force Microscopy to Follow Phase Changes at Crystal Surfaces in Real Time

2013 ◽  
Vol 52 (40) ◽  
pp. 10541-10544 ◽  
Author(s):  
Ranjit Thakuria ◽  
Mark D. Eddleston ◽  
Ernest H. H. Chow ◽  
Gareth O. Lloyd ◽  
Barry J. Aldous ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Real Time ◽  
Phase Changes ◽  
Crystal Surfaces ◽  
Force Microscopy ◽  
Atomic Force

Atomic Steps on a Silicon Surface as is Test-Object in Atomic Force Microscopy

2009 ◽  
Vol 4 (1) ◽  
pp. 47-55
Author(s):  
Dmitriy Nasimov ◽  
Dmitriy Sheglov ◽  
Aleksandr Latyshev
Keyword(s):  
Test Object ◽  
Lattice Parameter ◽  
Interplanar Distance ◽  
Perfect Crystal ◽  
Vicinal Surface ◽  
Atomic Lattice ◽  
Atomic Steps ◽  
Force Microscopy ◽  
Uniformity Of Measurements ◽  
Atomic Force

To ensure uniformity of measurements in nanotechnology test-object have been developed. It provide precise calibration of z-coordinates of the atomic force microscope in the sub-and nanometer bands with an accuracy of 0.05 nm on the basis of a system of atomic steps, one interplanar distance in height, at the vicinal surface of silicon. Extremely high precision of the test-object is provided by comparing its values with the atomic lattice parameter of the perfect crystal.

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