Article
Physics, Applied
C. S. Allen, M. Danaie, J. H. Warner, D. J. Batey, A. I. Kirkland
Summary: We demonstrate that electron ptychographic phase reconstruction can recover spatial frequencies higher than those directly recorded in the experimental electron diffraction patterns. This allows for the simultaneous recording of a conventional annular dark field image and a ptychographic dataset by inserting an annular detector that partially shadows a lower pixelated detector. We achieved an Abbe limited resolution of 1.2 +/- 0.1A degrees in our reconstructions of monolayer molybdenum disulfide at 30 keV.
APPLIED PHYSICS LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Han Liu, Ying Chen, Zhaohe Gao, Nadia Rohbeck, Ping Xiao
Summary: This study investigates the oxidation behavior of stoichiometric and hyper-stoichiometric silicon carbide (SiC) with silicon impurity. Silica growth on both SiCs was parabolic in air at 1200°C and 1600°C, but was faster on hyper-stoichiometric SiC. However, in steam, the oxidation kinetics were reversed due to the generation of gaseous products and pore networks in silica on stoichiometric SiC, resulting in a reaction-controlled linear oxidation behavior.
Article
Materials Science, Multidisciplinary
Thomas C. Valenza, Paul Chao, Peter K. Weber, Owen K. Neill, Emmanuelle A. Marquis
Summary: We investigated the oxidation behavior of pure titanium and Ti-0.8 at.% Si in Ar-O2 and O2 at 800 degrees C. The enhanced oxidation resistance of Ti-0.8 at.% Si was attributed to the formation of a continuous Ti5Si3 layer at the oxide-metal interface, which initially reduced outward oxide growth and eliminated inward growth. After the breakdown of the Ti5Si3 layer, the oxide on Ti-0.8 at.% Si became lamellar but remained more compact and possibly slower growing than the oxide on pure titanium.
Article
Chemistry, Physical
L. Khomenkova, H. Merabet, M. -P. Chauvat, C. Frilay, X. Portier, C. Labbe, P. Marie, J. Cardin, S. Boudin, J. -M. Rueff, F. Gourbilleau
Summary: The effect of Er precursor nature and annealing treatment on the properties of Er2O3 films grown on Si substrates was studied. Annealing resulted in film crystallization and the formation of Er silicate phase. The light emitting properties were determined by native defects and intra-4f shell transition. The intense Er3+ emission in the films grown with O2-plasma-assisted approach was attributed to a lower contribution of oxygen vacancies and pronounced crystallization of Er silicate phase.
SURFACES AND INTERFACES
(2022)
Article
Microscopy
Dennis Marquardt, Marco Schowalter, Florian F. Krause, Tim Grieb, Christoph Mahr, Thorsten Mehrtens, Andreas Rosenauer
Summary: This study investigates the impact of lens aberrations, beam tilt, contamination and shot noise on position determination in imaging scanning transmission electron microscopy (ISTEM) using BaTiO3 as an example. By simulating ISTEM images and defining a figure of merit, recommendations for experimental setup to measure atomic arrangements that induce ferroelectric switching of BaTiO3 were obtained.
Article
Nanoscience & Nanotechnology
Franz Bamer, Somar Shekh Alshabab, Arghadwip Paul, Firaz Ebrahem, Bernd Markert, Benjamin Stamm
Summary: This study investigates the mechanical behavior of silica glass through data-driven methods, accurately classifying and predicting whether elementary rearrangement events recover within specific deformation protocols. Rigorous statistical analysis and polynomial regression provide valuable insights into the mechanics of marginally stable strain states of silica glass.
SCRIPTA MATERIALIA
(2021)
Article
Chemistry, Multidisciplinary
Sytze de Graaf, Majid Ahmadi, Ivan Lazic, Eric G. T. Bosch, Bart J. Kooi
Summary: STEM is the most commonly used tool for atomic scale characterization of two-dimensional materials, but damage-free imaging remains a challenge, especially when observing combinations of light and heavy elements, particularly when recording fast dynamic phenomena.
Article
Chemistry, Physical
Jhih H. Liang, Zac Milne, Mehdi Rouhani, Yi-Pan Lin, Rodrigo A. Bernal, Takaaki Sato, Robert W. Carpick, Yeau R. Jeng
Summary: This study presents the first in situ transmission electron microscope (TEM) investigation of diamond-like carbon (DLC) sliding on diamond. The tribological properties of amorphous carbon (a-C) are explored under the harsh condition of sliding against diamond in a vacuum. Real-time TEM imaging provides insights into wear mechanisms and damage. The study reveals that high contact stresses lead to increased adhesion and accelerated wear of a-C on diamond.
Article
Chemistry, Multidisciplinary
Yi Wen, Shiang Fang, Matthew Coupin, Yang Lu, Colin Ophus, Efthimios Kaxiras, Jamie H. Warner
Summary: Four-dimensional (4D) scanning transmission electron microscopy was used to study the electric fields at the edges of 2D semiconducting monolayer MoS2. Sub-nanometer 1D features in the 2D electric field maps were observed at the outermost region along zigzag edges and also along nanowire MoS-terminated MoS2 edges. The presence of low Z number atoms terminating many of the uniform edges was revealed through electric field reconstructions, along with integrated differential phase contrast reconstructions. Density functional theory calculations supported the formation of periodic 1D edge states and indicated the enhancement of electric field magnitude for some edge terminations. The experimentally observed electric fields at the edges were attributed to the absence of an opposing electric field from a nearest neighbor atom when the electron beam propagates through the 2D monolayer and interacts. These results highlight the potential of 4D-STEM in mapping the atomic scale structure and fluctuations of electric fields around edge atoms in 2D materials.
Article
Chemistry, Multidisciplinary
Jong Chan Yoon, Zonghoon Lee, Gyeong Hee Ryu
Summary: The study reports the structural merging behavior and atomic arrangement of zinc oxide nanosheets transferred onto monolayer graphene, providing insights into atomic alignments and rearrangements when transitioning into a graphene-like layered structure.
Article
Chemistry, Physical
Yong Zhang, Pengfei Wu, Yu Lu, Xun Cao, Yizhong Huang, Vincent Gill, Zhiming Li
Summary: The atomic-scale structures of Z-plates in a Zr-alloyed Sm2Co17-type magnet were investigated using aberration-corrected STEM. Zr preferentially replaces dumbbell Sm to form (Sm1/3Zr2/3)Co3 Z-plates, which contribute to the enhancement of magnet performance. Different stacking types of Z-plates were observed, some of which exceed the thickness of double 2/3-stacking and degrade the oxidation resistance of the magnet. The diffusion-controlled mechanisms for the phase transformation from the 2:17R matrix to the 1:3R Z-plates were unraveled.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Multidisciplinary
Emad H. Bartawi, Oleg V. Mishin, Ghada Shaban, Jan H. Nordlien, Rajan Ambat
Summary: The microstructure and intergranular corrosion were studied in an extruded and aged Al-Mg-Si alloy doped with 0.05 wt% Cu after immersion in an acidified salt solution. Despite the low content of Cu, intergranular corrosion still occurs in this alloy. Electron microscopy analysis of the exposed surface in the corrosive environment does not show any significant difference in the fraction of corroded random and coincident site lattice high angle boundaries. Low angle boundaries with misorientations below 10 degrees are consistently found to be more resistant to intergranular corrosion than other boundary types.
Article
Chemistry, Physical
Radim Skoupy, Daan B. B. Boltje, Miroslav Slouf, Katerina Mrazova, Tomas Laznicka, Clemence M. Taisne, Vladislav Krzyzanek, Jacob P. P. Hoogenboom, Arjen J. J. Jakobi
Summary: This study presents a quantitative four-dimensional scanning transmission electron microscopy (4D-STEM) imaging technique (q4STEM) for local thickness estimation across amorphous specimens. The method measures spatially resolved diffraction patterns and evaluates the angular distribution of electron scattering or the ratio of integrated virtual dark and bright field STEM signals using Monte Carlo simulations. The method is independent of signal intensity calibrations and only requires knowledge of the detector geometry. The results demonstrate that the method yields robust thickness estimates for sub-micrometer amorphous specimens in different detectors and instruments.
Article
Chemistry, Physical
D. Gonzalez, S. Flores, N. Ruiz-Marin, D. F. Reyes, L. Stanojevic, A. D. Utrilla, A. Gonzalo, A. Gallego Carro, J. M. Ulloa, T. Ben
Summary: This study compared two different strategies to protect InAs/GaAs quantum dots from decomposition during the capping process, and found that QD volume is a better parameter to assess QD decomposition and PL redshift. Additionally, a decrease in QD density was observed with an increase in average volume.
APPLIED SURFACE SCIENCE
(2021)
Article
Materials Science, Multidisciplinary
Chao Liu, Peng Jin, Tielong Shen, Zhiguang Wang
Summary: The microstructural evolution and dissolved oxygen of the oxide film formed on 15-15Ti austenitic stainless steel during early oxidation in steam at 500 degrees C were investigated. A triplex oxide structure consisting of outer Fe-rich layer, inner Cr-rich layer, and Ni-rich transition layer was observed. The relationship between corrosion resistance and oxide structure was discussed, and a mechanism for pore formation in the inner oxide layer of austenitic steel was proposed based on Ni's spatial distribution and migration behavior during oxidation.
Article
Microscopy
C. Gao, C. Hofer, T. J. Pennycook
Summary: Ptychography provides high dose efficiency images that can reveal light elements next to heavy atoms. However, contrast reversals can occur when the projected potential becomes strong. Recent research has shown that these reversals can be counteracted by adapting the focus. This study explains why the best contrast is often found with the probe focused to the middle of the sample and highlights the importance of convergence angle in thin samples to remove contrast reversals.
Article
Microscopy
J. Lindner, U. Ross, T. Meyer, V. Boureau, M. Seibt, Ch. Jooss
Summary: Phase-shifting electron holography is an excellent method with high phase sensitivity to reveal electron wave phase information. An advanced drift correction scheme is proposed in this study, which exploits the interface of the TEM specimen and the vacuum area in the hologram. This method allows for obtaining reliable phase information.
Article
Microscopy
Ali Jaberi, Nicolas Brodusch, Jun Song, Raynald Gauvin
Summary: This study investigates knock-on damage in lithium-ion batteries (LIBs) by computing threshold displacement energies (TDEs) and performing Monte Carlo simulation. The results indicate that Li is most sensitive to knock-on damage at moderate electron energies, and TDE is the principal parameter for assessing Li sensitivity to knock-on damage across similar structures.
Article
Microscopy
Alexander Schroeder, Christopher Rathje, Leon van Velzen, Maurits Kelder, Sascha Schaefer
Summary: This study utilizes novel event-based electron detector platforms to extend the temporal resolution of electron microscopy. By training a neural network to predict electron arrival time, the researchers were able to improve the timing accuracy and achieve a promising solution for enhancing electron timing precision in various electron microscopy applications.
Article
Microscopy
Avi Auslender, Nivedita Pandey, Amit Kohn, Oswaldo Dieguez
Summary: This article describes a faster implementation based on DFT for computing the mean inner potential of crystals, providing quantum-mechanical calculations beyond the independent-atom approximation. The study also reveals the dependence of the mean inner potential on sample boundary conditions, mass density, and magnetic susceptibility, highlighting its correlation with various material properties.
Article
Microscopy
Zhidong Yang, Dawei Zang, Hongjia Li, Zhao Zhang, Fa Zhang, Renmin Han
Summary: In this work, we propose a self-supervised deep learning model for cryo-ET volumetric image denoising based on noise modeling and sparsity guidance. Experimental results demonstrate that our method can achieve reliable denoising by training on single noisy volume and outperform existing methods.
Article
Microscopy
J. Kuttruff, J. Holder, Y. Meng, P. Baum
Summary: In this study, a robust clustering algorithm is proposed that can find clusters in a continuous stream of raw data in real time. This algorithm converts pixel hits measured by hybrid pixel detectors to real single-electron events. By continuously comparing with previous hits, the algorithm efficiently identifies the merging of new and old events.
Article
Microscopy
D. G. Senturk, C. P. Yu, A. De Backer, S. Van Aert
Summary: This article presents a statistics-based method for accurately counting the number of atoms in nanostructures, especially for images acquired with low electron doses and multiple element structures.
Article
Microscopy
Mauricio J. Prieto, Lucas de Souza Caldas, Liviu C. Tanase, Thomas Schmidt, Oscar Rodriguez de la Fuente
Summary: This study presents a synchrotron-based investigation of the synthesis process of a magnetite/hematite bilayer. Ion bombardment gradually transforms hematite into magnetite, and the growth of magnetite leads to the formation of stable boundaries. These findings are significant for understanding novel oxide heterostructures.
Article
Microscopy
Emre Yoruk, Holger Klein, Stephanie Kodjikian
Summary: Beam sensitive nanomaterials pose challenges for crystallographic structure determination. A dose symmetric electron diffraction tomography (DS-EDT) method is developed to reduce beam damage and obtain complete data sets by merging individual datasets from multiple crystals.
Article
Microscopy
A. Pofelski, Y. Zhu, G. A. Botton
Summary: The precision and sensitivity of the GPA method for strain characterization is a widely discussed topic. This study introduces the concept of phase noise and analyzes the parameter of sampling to improve the precision of GPA. Experimental and theoretical results demonstrate that using a larger pixel spacing in STEM can enhance the precision and sensitivity of the GPA method.
Article
Microscopy
Sangjun Kang, Di Wang, Christian Kuebel, Xiaoke Mu
Summary: Transmission electron microscopy is a valuable tool for assessing strain fields within materials. However, using thin specimens in TEM analysis can affect atomic configuration and deformation structure.
