scholarly journals Scanning force microscopy of microtubules and polymorphic tubulin assemblies in air and in liquid

1995 ◽  
Vol 108 (3) ◽  
pp. 1063-1069
Author(s):  
W. Vater ◽  
W. Fritzsche ◽  
A. Schaper ◽  
K.J. Bohm ◽  
E. Unger ◽  
...  
Keyword(s):  
Scanning Force Microscopy ◽  
Force Microscopy ◽  
A Value ◽  
Transmission Electron ◽  
Associated Proteins ◽  
Scanning Force ◽  
Fibrous Morphology ◽  
Ultrathin Sections ◽  
20 Nm

We have investigated microtubules (MTs) and polymorphic assemblies, formed in vitro from isolated microtubule protein, by scanning force microscopy (SFM) in air and in liquid. Immobilization of MTs was achieved by placing a drop of the assembly solution on a polylysine-coated coverslip. After washing with taxol and air drying, the characteristic microtubular fibrous morphology appeared in the SFM. The MTs formed a network similar to that obtained by transmission electron microscopy (TEM). A height of approximately 9.5 nm for dried MTs was computed from the surface topography. Glutaraldehyde fixation of the MTs yielded higher structures (approximately 14 nm), which swelled to approximately 20 nm after rehydration, a value close to the MT diameter of approximately 25 nm determined from TEM images of ultrathin sections. The protofilament pattern of the MTs and surface attached MT-associated proteins were not apparent from SFM, although the height along the long axis of the MTs appeared slightly modulated. In addition to MTs, various polymorphic tubulin assemblies including ribbons, hoops and double-walled MTs were visualized by SFM.

Examination of Atomic (Scanning) Force Microscopy Probe Tips with the Transmission Electron Microscope

1997 ◽  
Vol 3 (3) ◽  
pp. 203-213 ◽  
Author(s):  
J.A. DeRose ◽  
J.-P. Revel
Keyword(s):  
Atomic Force Microscopy ◽  
Electron Microscope ◽  
High Resolution ◽  
Transmission Electron Microscope ◽  
Scanning Force Microscopy ◽  
Image Deconvolution ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Scanning Force

Abstract: We have developed a method for the examination of atomic force microscopy (scanning force microscopy) tips using a high-resolution transmission electron microscope (TEM). The tips can be imaged in a nondestructive way, enabling one to observe the shape of an atomic force microscope probe in the vicinity of the apex with high resolution. We have obtained images of atomic force microscopy probes with a resolution on the order of 1 nm. The tips can be imaged repeatedly, so one can examine tips before and after use. We have found that the tip can become blunted with use, the rate of wear depending upon the sample and tip materials and the scanning conditions. We have also found that the tips easily accrue contamination. We have studied both commercially produced tips, as well as tips grown by electron beam deposition. Direct imaging in the TEM should prove useful for image deconvolution methods because one does not have to make any assumptions concerning the general shape of the tip profile.

scholarly journals Transmission electron microscopy and scanning force microscopy of poly r(A-U) and poly r(A-U)-ethidium bromide

Scanning ◽  
2006 ◽  
Vol 19 (8) ◽  
pp. 523-532 ◽  
Author(s):  
J. Gilloteaux ◽  
J. M. Jamison ◽  
F. Zenhausern ◽  
M. Adrian ◽  
J. L. Summers
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Ethidium Bromide ◽  
Scanning Force Microscopy ◽  
Force Microscopy ◽  
Transmission Electron ◽  
Scanning Force

Structure and Novel Electrical Effects in A-Si:H Based Multilayers Containing Discontinuous Metal Sublayers

1995 ◽  
Vol 382 ◽  
Author(s):  
A.N. Panckow ◽  
T.P. DrÜsedau ◽  
F. Klabunde ◽  
B. SchrÖder
Keyword(s):  
Scanning Force Microscopy ◽  
Temperature Dependent ◽  
Multilayer Systems ◽  
Force Microscopy ◽  
Transmission Electron ◽  
Nominal Thickness ◽  
Structural Peculiarities ◽  
Rf Glow Discharge ◽  
Scanning Force ◽  
Hydrogenated Amorphous

ABSTRACTMultilayer systems (MLS) were prepared by alternating deposition of hydrogenated amorphous silicon (a-Si:H) and transition metal (Mo,Ti,V) sublayers. The thickness of the a-Si:H sublayers deposited by either dc-magnetron sputtering or rf-glow discharge deposition is in the range from 65 nm to 85 nm. The nanodisperse structure of the metal sublayers with a nominal thickness below 4 nm was verified by transmission electron microscopy, scanning force microscopy and spectroscopic ellipsometry. The discontinuous metal sublayers were formed by chains of metal clusters. The appearance of novel electrical phenomena was observed. These are a reversible switching effect in conduction and giant current fluctuations. The validity of the T−1/2 -law for the temperature dependent conductivity was confirmed. In this study explanations for some of these effects are given considering the structural peculiarities of the nanodisperse multilayers.

Microstructural issues in c-parallel YBa2Cu3O7-δ thin films

1992 ◽  
Vol 50 (1) ◽  
pp. 240-241
Author(s):  
S.K. Streiffer ◽  
B.M. Lairson ◽  
E.M. Zielinski ◽  
T. Umezawa ◽  
T.H. Geballe ◽  
...  
Keyword(s):  
Scanning Force Microscopy ◽  
Critical Currents ◽  
Nucleation Layer ◽  
Force Microscopy ◽  
Transmission Electron ◽  
Single Target ◽  
Initial Nucleation ◽  
Axis Parallel ◽  
Scanning Force ◽  
Dense Films

Considerable effort has been directed at understanding the microstructures present in YBa2Cu3O7-δ films with the c-axis perpendicular to the plane of the substrate. This work has largely been driven by the high critical currents achieved in this particular film orientation. Although the critical currents are in general lower, the demonstration of high crystal quality, extremely smooth, dense films with their c-axis parallel to the plane of the substrate has opened the possibility of exploiting the highly anisotropic nature of YBa2Cu3O7-δ. To fully utilize such films, a thorough investigation of microstructural issues is as necessary for this film orientation as for the c-perpendicular case. We have used transmission electron microscopy and scanning force microscopy to examine c-parallel films grown on SrTiO3 and LaAlO3 substrates by single-target, off-axis magnetron sputtering. Films were deposited at block temperatures ranging from 600°C to 640°C, in atmospheres ranging from 30 millitorr oxygen and 40 millitorr argon to 60 millitorr oxygen and 90 millitorr argon. In an effort to improve superconducting properties while maintaining as smooth a surface as possible, films were also grown by a template method in which an initial nucleation layer was deposited at 625°C and the remainder of the film deposited at 700°C.

Polypropylene-Functionalized Probes for Scanning Force Microscopy

2001 ◽  
Vol 710 ◽  
Author(s):  
L. González-Ronda ◽  
S. L. Kaberline ◽  
E. L. Durieux
Keyword(s):  
Secondary Ion Mass Spectrometry ◽  
Three Dimensional ◽  
Dynamic Contact Angle ◽  
Scanning Force Microscopy ◽  
Dynamic Contact ◽  
Force Microscopy ◽  
Before And After ◽  
Evaluation Algorithm ◽  
Scanning Force ◽  
20 Nm

ABSTRACTSFM probe tips have been functionalized with polypropylene (PP) layers by immersion into dilute solution. The immersion process was carefully controlled and monitored using a programmable dynamic contact angle analyzer (DCA) equipped with a microbalance and a motor capable of speeds ranging from 2-24 μm/s. Probes were submitted to treatment with ozone prior to coating to eliminate surface contamination, particularly silicone oils, resulting from commercial packaging methods. The chemical composition of the tip surface after the cleaning, coating, and scanning processes was analyzed by Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS). The three-dimensional tip shape and dimensions before and after coating were evaluated by blind reconstruction from images of a columnar titanium thin film using Digital Instruments' Tip Evaluation algorithm. Coating thicknesses of up to 20 nm were calculated, with the thicker coatings showing a larger degree of non-uniformity.

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.

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