High-resolution microscopy of ceramic surfaces

1993 ◽  
Vol 51 ◽  
pp. 962-963
Author(s):  
J. Bentley
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Film Growth ◽  
Specimen Preparation ◽  
Force Microscopy ◽  
Advantages And Disadvantages ◽  
Transmission Electron ◽  
Ceramic Surfaces ◽  
Wide Range ◽  
Scanning Transmission

The characterization of ceramic surfaces plays an important role in understanding a wide variety of properties such as fracture, wear, crack initiation, oxidation, sintering, and thin film growth on substrates. Three major microscopies are employed to obtain nanometer-scale resolution of ceramic surfaces: scanning electron microscopy (SEM), (scanning) transmission electron microscopy (STEM or TEM) especially in the glancing-incidence reflection modes, and scanning tip microscopies - most notably atomic force microscopy (AFM). Each technique has its own set of characteristics, advantages, and disadvantages and is usually complementary to the others.Conventional SEM is quick and easy to implement. As a mature technique, the contrast mechanisms, although sometimes complex, are largely well understood; computer programs for image simulation are available. The technique is applicable to a wide range of materials and specimen sizes; usually, little specimen preparation is involved. Charging of electrically insulating ceramics has traditionally been overcome by coating but, at high resolution, the faithful representation of the structure then becomes of some concern.

Site Specific TEM Specimen Preparation using an FIB/TEM System

2000 ◽  
Vol 6 (S2) ◽  
pp. 510-511 ◽  
Author(s):  
T. Kamino ◽  
T. Yaguchi ◽  
T. Ohnishi ◽  
K. Umemura ◽  
S. Tomimatsu
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Specimen Preparation ◽  
Site Specific ◽  
Specimen Holder ◽  
Transmission Electron ◽  
Wide Range ◽  
Scanning Transmission

The focused ion beam(FIB) technique, developed for the microelectronics industry has become a major method for site specific transmission electron microscopy(TEM) specimen preparation in a wide range of materials[l]. The FIB lift-out technique has improved the specimen preparation procedures by removing complicated initial fabrication required prior to the FIB milling[2]. However, conventional FIB techniques are still having increased difficulty in meeting failure analysis needs from high technology industries such as microelectronics.We have developed a site specific TEM specimen preparation method using a combination of an FIB instrument and an intermediate voltage TEM equipped with a scanning attachment [3]. In this method, the specimen is mounted on an FIB-TEM compatible specimen holder, so that localization of the specific site can be carried out in the FIB and TEM using the same holder. The scanning electron imaging mode may be used to observe surface structures of the milled area, and the scanning transmission electron microscopy(STEM) mode may be used to observe structures inside of the milled surface.

Preparation of Titanium Microgrids for Scanning Transmission Electron Microscopy

1977 ◽  
Vol 35 ◽  
pp. 322-323
Author(s):  
M.L. Collins ◽  
N.W. Parker
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Scanning Transmission Electron Microscopy ◽  
Single Atom ◽  
Specimen Preparation ◽  
Transmission Microscopy ◽  
Scanning Transmission Electron ◽  
Transmission Electron ◽  
Scanning Transmission

The ideal supporting microgrid for high resolution scanning transmission electron microscopy should be: 1) made of material of low atomic number, 2) uniformly flat for ease in focusing, 3) resistant to any treatments necessary for cleaning and specimen preparation, and 4) a good electrical and thermal conductor. In the past, microgrid supports have been made of fenestrated plastic films strengthened by carbon or metal coatings. While adequate for most work, they cannot be baked at temperatures greater than 50°C. which may be necessary in some cases to completely eliminate contamination for single atom imaging using the STEM. To provide a reliably non-contaminating substrate support for high resolution scanning transmission microscopy, we have developed a simple technique for the preparation of microgrids of titanium metal. As can be seen in table 1, titanium posesses many attractive features.

scholarly journals Measuring the Autocorrelation Function of Nanoscale Three-Dimensional Density Distribution in Individual Cells Using Scanning Transmission Electron Microscopy, Atomic Force Microscopy, and a New Deconvolution Algorithm

2017 ◽  
Vol 23 (3) ◽  
pp. 661-667 ◽  
Author(s):  
Yue Li ◽  
Di Zhang ◽  
Ilker Capoglu ◽  
Karl A. Hujsak ◽  
Dhwanil Damania ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Density Distribution ◽  
Scanning Transmission Electron Microscopy ◽  
Mass Density ◽  
Three Dimensional ◽  
Force Microscopy ◽  
Statistical Measures ◽  
Atomic Force ◽  
Transmission Electron ◽  
Scanning Transmission

AbstractEssentially all biological processes are highly dependent on the nanoscale architecture of the cellular components where these processes take place. Statistical measures, such as the autocorrelation function (ACF) of the three-dimensional (3D) mass–density distribution, are widely used to characterize cellular nanostructure. However, conventional methods of reconstruction of the deterministic 3D mass–density distribution, from which these statistical measures can be calculated, have been inadequate for thick biological structures, such as whole cells, due to the conflict between the need for nanoscale resolution and its inverse relationship with thickness after conventional tomographic reconstruction. To tackle the problem, we have developed a robust method to calculate the ACF of the 3D mass–density distribution without tomography. Assuming the biological mass distribution is isotropic, our method allows for accurate statistical characterization of the 3D mass–density distribution by ACF with two data sets: a single projection image by scanning transmission electron microscopy and a thickness map by atomic force microscopy. Here we present validation of the ACF reconstruction algorithm, as well as its application to calculate the statistics of the 3D distribution of mass–density in a region containing the nucleus of an entire mammalian cell. This method may provide important insights into architectural changes that accompany cellular processes.

scholarly journals On the Operational Aspects of Measuring Nanoparticle Sizes

Nanomaterials ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 18 ◽  
Author(s):  
Jean-Marie Teulon ◽  
Christian Godon ◽  
Louis Chantalat ◽  
Christine Moriscot ◽  
Julien Cambedouzou ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Ag Nps ◽  
Force Microscopy ◽  
Average Value ◽  
Atomic Force ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Experimental Protocols ◽  
Operational Aspects

Nanoparticles are defined as elementary particles with a size between 1 and 100 nm for at least 50% (in number). They can be made from natural materials, or manufactured. Due to their small sizes, novel toxicological issues are raised and thus determining the accurate size of these nanoparticles is a major challenge. In this study, we performed an intercomparison experiment with the goal to measure sizes of several nanoparticles, in a first step, calibrated beads and monodispersed SiO2 Ludox®, and, in a second step, nanoparticles (NPs) of toxicological interest, such as Silver NM-300 K and PVP-coated Ag NPs, Titanium dioxide A12, P25(Degussa), and E171(A), using commonly available laboratory techniques such as transmission electron microscopy, scanning electron microscopy, small-angle X-ray scattering, dynamic light scattering, wet scanning transmission electron microscopy (and its dry state, STEM) and atomic force microscopy. With monomodal distributed NPs (polystyrene beads and SiO2 Ludox®), all tested techniques provide a global size value amplitude within 25% from each other, whereas on multimodal distributed NPs (Ag and TiO2) the inter-technique variation in size values reaches 300%. Our results highlight several pitfalls of NP size measurements such as operational aspects, which are unexpected consequences in the choice of experimental protocols. It reinforces the idea that averaging the NP size from different biophysical techniques (and experimental protocols) is more robust than focusing on repetitions of a single technique. Besides, when characterizing a heterogeneous NP in size, a size distribution is more informative than a simple average value. This work emphasizes the need for nanotoxicologists (and regulatory agencies) to test a large panel of different techniques before making a choice for the most appropriate technique(s)/protocol(s) to characterize a peculiar NP.

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