Transmission electron microscopy of extended defects in alkali halide crystals

2007 ◽  
pp. 152-250 ◽  
Author(s):  
L. W. Hobbs
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Alkali Halide ◽  
Extended Defects ◽  
Transmission Electron ◽  
Alkali Halide Crystals

Minimizing Transmission Electron Microscopy Beam Damage during the Study of Surface Reactions on Sodium Chloride

1998 ◽  
Vol 4 (1) ◽  
pp. 23-33 ◽  
Author(s):  
Heather C. Allen ◽  
Martha L. Mecartney ◽  
John C. Hemminger
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Water Vapor ◽  
Sodium Chloride ◽  
Single Crystals ◽  
Alkali Halide ◽  
Surface Reactions ◽  
Transmission Electron ◽  
Alkali Halide Crystals ◽  
Beam Damage

Electron beam damage is a significant limitation for transmission electron microscopy (TEM) studies of beam-sensitive samples. An approach for studying surface reactions on alkali halide crystals using 200 kV TEM is presented. Experiments were designed to monitor the reaction of NaCl crystals with HNO3 gas followed by water vapor to form solid NaNO3. During beam damage experiments, TEM micrographs record structural changes to both NaCl and NaNO3, including dislocation loops, void formation, and decomposition. Sample decomposition can be successfully minimized by a combination of commonly used techniques: (1) focusing the beam adjacent to the area of interest, (2) lowering the electron density, (3) choosing to image larger (micrometer- versus submicrometer-sized) alkali halide crystals, and (4) lowering temperature by the use of a liquid nitrogen cooling stage. From these results, additional studies were designed that monitored sequential experiments. Sensitive micrometer-sized sodium chloride single crystals before and after exposure to nitric acid vapor and water vapor and the subsequent growth of submicrometer-sized sodium nitrate single crystals could then be successfully imaged using TEM.

scholarly journals Compressed Sensing of Scanning Transmission Electron Microscopy (STEM) With Nonrectangular Scans

2018 ◽  
Vol 24 (6) ◽  
pp. 623-633 ◽  
Author(s):  
Xin Li ◽  
Ondrej Dyck ◽  
Sergei V. Kalinin ◽  
Stephen Jesse
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Real Time ◽  
Scanning Transmission Electron Microscopy ◽  
High Speed ◽  
Dynamic Range ◽  
Extended Defects ◽  
Scanning Transmission Electron ◽  
Transmission Electron ◽  
Scanning Transmission

AbstractScanning transmission electron microscopy (STEM) has become the main stay for materials characterization on atomic level, with applications ranging from visualization of localized and extended defects to mapping order parameter fields. In recent years, attention has focused on the potential of STEM to explore beam induced chemical processes and especially manipulating atomic motion, enabling atom-by-atom fabrication. These applications, as well as traditional imaging of beam sensitive materials, necessitate increasing the dynamic range of STEM in imaging and manipulation modes, and increasing the absolute scanning speed which can be achieved by combining sparse sensing methods with nonrectangular scanning trajectories. Here we have developed a general method for real-time reconstruction of sparsely sampled images from high-speed, noninvasive and diverse scanning pathways, including spiral scan and Lissajous scan. This approach is demonstrated on both the synthetic data and experimental STEM data on the beam sensitive material graphene. This work opens the door for comprehensive investigation and optimal design of dose efficient scanning strategies and real-time adaptive inference and control of e-beam induced atomic fabrication.

Effect of Dopant Concentrations and Annealing Conditions on the Electrically Active Profiles and Lattice Damage in Al Implanted 4H-SiC

2010 ◽  
Vol 645-648 ◽  
pp. 713-716 ◽  
Author(s):  
Ming Hung Weng ◽  
Fabrizio Roccaforte ◽  
Filippo Giannazzo ◽  
Salvatore di Franco ◽  
Corrado Bongiorno ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Depth Distribution ◽  
Electrical Activation ◽  
Extended Defects ◽  
Capping Layer ◽  
Annealing Conditions ◽  
Transmission Electron ◽  
Lattice Damage ◽  
Reduced Surface

This paper reports on the electrical activation and structural analysis of Al implanted 4H-SiC. The evolution of the implant damage during high temperature (1650 – 1700 °C) annealing results in the presence of extended defects and precipitates, whose density and depth distribution in the implanted sheet was accurately studied for two different ion fluences (1.31014 and 1.31015 cm-2) by transmission electron microscopy. Furthermore, the profiles of electrically active Al were determined by scanning capacitance microscopy. Only a limited electrical activation (10%) was measured for both fluences in the samples annealed without a capping layer. The use of a graphite capping layer to protect the surface during annealing showed a beneficial effect, yielding both a reduced surface roughness and an increased electrical activation (20% for the highest fluence and 30% for the lowest one) with respect to samples annealed without the capping layer.

Transmission Electron Microscopy Investigations of Metal-Impurity-Related Defects in Crystalline Silicon

2011 ◽  
Vol 178-179 ◽  
pp. 275-284 ◽  
Author(s):  
Michael Seibt ◽  
Philipp Saring ◽  
Philipp Hahne ◽  
Linda Stolze ◽  
M.A. Falkenberg ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Focused Ion Beam ◽  
Crystalline Silicon ◽  
Ion Beam ◽  
Extended Defects ◽  
Metal Impurity ◽  
Transmission Electron ◽  
Electron Beam Induced Current

This contribution summarizes recent efforts to apply transmission electron microscopy (TEM) techniques to recombination-active extended defects present in a low density. In order to locate individual defects, electron beam induced current (EBIC) is applied in situ in a focused ion beam (FIB) machine combined with a scanning electron microscope. Using this approach defect densities down to about 10cm-2 are accessible while a target accuracy of better than 50nm is achieved. First applications described here include metal impurity related defects in multicrystalline silicon, recombination and charge collection at NiSi2 platelets, internal gettering of copper by NiSi2 precipitates and site-determination of copper atoms in NiSi2.

Transmission electron microscopy and cathodoluminescence studies of extended defects in electron-beam-pumped Zn1−xCdxSe/ZnSe blue-green lasers

1998 ◽  
Vol 83 (4) ◽  
pp. 1945-1952 ◽  
Author(s):  
Jean-Marc Bonard ◽  
Jean-Daniel Ganière ◽  
Lia Vanzetti ◽  
Jens J. Paggel ◽  
Lucia Sorba ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Beam ◽  
Extended Defects ◽  
Transmission Electron
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