Nanoscale 3D Chemical Mapping by Spectroscopic Electron Tomography

2002 ◽  
Vol 738 ◽  
Author(s):  
Günter Möbus ◽  
Ron C. Doole ◽  
Beverley J. Inkson

ABSTRACTElectron Tomography is shown to be applicable to problems of materials science if a contrast mechanism is used which provides a projection relationship for crystals not depending on lattice plane orientation. Energy filtered TEM (EFTEM) in its mode of electron spectroscopic imaging (ESI) and STEM-EDX-Mapping are, subject to limitations, suitable image formation techniques. The spectroscopic operation not only allows to overcome Bragg scattering artefacts, but offers the possibility of recording 4-dimensional data (volume and energy) of a region of interest, otherwise only known from NMR and XAS/XANES tomography at larger length-scales and from field-ion microscopy (atom probe) under restrictive conditions.

Author(s):  
M. Rühle ◽  
J. Mayer ◽  
J.C.H. Spence ◽  
J. Bihr ◽  
W. Probst ◽  
...  

A new Zeiss TEM with an imaging Omega filter is a fully digitized, side-entry, 120 kV TEM/STEM instrument for materials science. The machine possesses an Omega magnetic imaging energy filter (see Fig. 1) placed between the third and fourth projector lens. Lanio designed the filter and a prototype was built at the Fritz-Haber-Institut in Berlin, Germany. The imaging magnetic filter allows energy-filtered images or diffraction patterns to be recorded without scanning using efficient area detection. The energy dispersion at the exit slit (Fig. 1) results in ∼ 1.5 μm/eV which allows imaging with energy windows of ≤ 10 eV. The smallest probe size of the microscope is 1.6 nm and the Koehler illumination system is used for the first time in a TEM. Serial recording of EELS spectra with a resolution < 1 eV is possible. The digital control allows X,Y,Z coordinates and tilt settings to be stored and later recalled.


Author(s):  
Woo Jun Kwon ◽  
Jisu Ryu ◽  
Christopher H. Kang ◽  
Michael B. Schmidt ◽  
Nicholas Croy

Abstract Focused ion beam (FIB) microscopy is an essential technique for the site-specific sample preparation of atom probe tomography (APT). The site specific APT and automated APT sample preparation by FIB have allowed increased APT sample volume. In the workflow of APT sampling, it is very critical to control depth of the sample where exact region of interest (ROI) for accurate APT analysis. Very precise depth control is required at low kV cleaning process in order to remove the damaged layer by previous high kV FIB process steps. We found low kV cleaning process with 5 kV and followed by 2kV beam conditions delivers better control to reached exact ROI on Z direction. This understanding is key to make APT sample with fully automated fashion.


2005 ◽  
Vol 11 (S02) ◽  
Author(s):  
P A Midgley ◽  
T Yates ◽  
I Arslan ◽  
J Tong ◽  
J M Thomas

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1304 ◽  
Author(s):  
Giulio Guzzinati ◽  
Thomas Altantzis ◽  
Maria Batuk ◽  
Annick De Backer ◽  
Gunnar Lumbeeck ◽  
...  

The rapid progress in materials science that enables the design of materials down to the nanoscale also demands characterization techniques able to analyze the materials down to the same scale, such as transmission electron microscopy. As Belgium’s foremost electron microscopy group, among the largest in the world, EMAT is continuously contributing to the development of TEM techniques, such as high-resolution imaging, diffraction, electron tomography, and spectroscopies, with an emphasis on quantification and reproducibility, as well as employing TEM methodology at the highest level to solve real-world materials science problems. The lab’s recent contributions are presented here together with specific case studies in order to highlight the usefulness of TEM to the advancement of materials science.


2001 ◽  
Vol 7 (S2) ◽  
pp. 88-89
Author(s):  
Ingo Daberkow ◽  
Bernhard Feja ◽  
Peter Sparlinek ◽  
Hans R. Tietz

During the last decade, computation of a three-dimensional image from a tilt series (3D reconstruction) has become a well established method, of which a variety of implementations are available. The term “electron tomography” is now generally used for this type of data acquisition and 3D reconstruction. An overview over the techniques involved is given in.With the introduction of micro-processor-controlled TEMs and cooled slow-scan CCD cameras and with the progress in performance of high-speed computers, automation of complex imaging procedures became mainly a task of developing appropriate software, using the control facilities of the microscope. in this way, automated electron tomography was realized in 1990 at the Max- Planck-Institute for Biochemistry in Martinsried, and at about the same time at the University of California in San Francisco (UCSF). New techniques for automatic focusing and alignment, developed somewhat earlier , have been integrated in these automated tomography procedures. in the following we discuss the requirements of automatic data acquisition and the present implementation for several TEMs.


2020 ◽  
Vol 92 (7) ◽  
pp. 5168-5177 ◽  
Author(s):  
Shi Qiu ◽  
Changxi Zheng ◽  
Vivek Garg ◽  
Yu Chen ◽  
Gediminas Gervinskas ◽  
...  

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Phillip Dumitraschkewitz ◽  
Peter J. Uggowitzer ◽  
Stephan S. A. Gerstl ◽  
Jörg F. Löffler ◽  
Stefan Pogatscher

Abstract A key question in materials science is how fast properties evolve, which relates to the kinetics of phase transformations. In metals, kinetics is primarily connected to diffusion, which for substitutional elements is enabled via mobile atomic-lattice vacancies. In fact, non-equilibrium vacancies are often required for structural changes. Rapid quenching of various important alloys, such as Al- or Mg-alloys, results for example in natural aging, i.e. slight movements of solute atoms in the material, which significantly alter the material properties. In this study we demonstrate a size effect of natural aging in an AlMgSi alloy via atom probe tomography with near-atomic image resolution. We show that non-equilibrium vacancy diffusional processes are generally stopped when the sample size reaches the nanometer scale. This precludes clustering and natural aging in samples below a certain size and has implications towards the study of non-equilibrium diffusion and microstructural changes via microscopy techniques.


2016 ◽  
Vol 160 ◽  
pp. 23-34 ◽  
Author(s):  
Tony Printemps ◽  
Guido Mula ◽  
Daniele Sette ◽  
Pierre Bleuet ◽  
Vincent Delaye ◽  
...  

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