scholarly journals Imaging an unsupported metal–metal bond in dirhenium molecules at the atomic scale

2020 ◽  
Vol 6 (3) ◽  
pp. eaay5849 ◽  
Author(s):  
Kecheng Cao ◽  
Stephen T. Skowron ◽  
Johannes Biskupek ◽  
Craig T. Stoppiello ◽  
Christopher Leist ◽  
...  
Keyword(s):  
Bond Order ◽  
High Amplitude ◽  
Atomic Scale ◽  
Bond Breaking ◽  
Microscopy Imaging ◽  
Transmission Electron ◽  
Metal Metal ◽  
Powerful Analytical Tool ◽  
Metallic Bonding ◽  
Aberration Corrected

Metallic bonds remain one of the most important and least understood of the chemical bonds. In this study, we generated Re2 molecules in which the Re–Re core is unsupported by ligands. Real-time imaging of the atomic-scale dynamics of Re2 adsorbed on a graphitic lattice allows direct measurement of Re–Re bond lengths for individual molecules that changes in discrete steps correlating with bond order from one to four. Direct imaging of the Re–Re bond breaking process reveals a new bonding state with the bond order less than one and a high-amplitude vibrational stretch, preceding the bond dissociation. The methodology, based on aberration-corrected transmission electron microscopy imaging, is shown to be a powerful analytical tool for the investigation of dynamics of metallic bonding at the atomic level.

scholarly journals Atomic-Scale Analysis of Chemical Bonding of Delaminated Graphene at Faceted SiC by Aberration-Corrected Scanning Transmission Electron Microscopy

2013 ◽  
Vol 19 (S2) ◽  
pp. 1238-1239
Author(s):  
G. Nicotra ◽  
Q.M. Ramasse ◽  
I. Deretzis ◽  
C. Bongiorno ◽  
C. Spinella ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Chemical Bonding ◽  
Scanning Transmission Electron Microscopy ◽  
Atomic Scale ◽  
Scale Analysis ◽  
Scanning Transmission Electron ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Aberration Corrected

Extended abstract of a paper presented at Microscopy and Microanalysis 2013 in Indianapolis, Indiana, USA, August 4 – August 8, 2013.

scholarly journals Probing magnetism in atomically thin semiconducting PtSe2

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Ahmet Avsar ◽  
Cheol-Yeon Cheon ◽  
Michele Pizzochero ◽  
Mukesh Tripathi ◽  
Alberto Ciarrocchi ◽  
...  
Keyword(s):  
Long Range ◽  
Magnetic Moments ◽  
Transition Metal Dichalcogenides ◽  
Magnetic Ordering ◽  
Atomic Scale ◽  
First Principles Calculations ◽  
Microscopy Imaging ◽  
Transmission Electron ◽  
Metal Dichalcogenides ◽  
The One

Abstract Atomic-scale disorder in two-dimensional transition metal dichalcogenides is often accompanied by local magnetic moments, which can conceivably induce long-range magnetic ordering into intrinsically non-magnetic materials. Here, we demonstrate the signature of long-range magnetic orderings in defective mono- and bi-layer semiconducting PtSe2 by performing magnetoresistance measurements under both lateral and vertical measurement configurations. As the material is thinned down from bi- to mono-layer thickness, we observe a ferromagnetic-to-antiferromagnetic crossover, a behavior which is opposite to the one observed in the prototypical 2D magnet CrI3. Our first-principles calculations, supported by aberration-corrected transmission electron microscopy imaging of point defects, associate this transition to the interplay between the defect-induced magnetism and the interlayer interactions in PtSe2. Furthermore, we show that graphene can be effectively used to probe the magnetization of adjacent semiconducting PtSe2. Our findings in an ultimately scaled monolayer system lay the foundation for atom-by-atom engineering of magnetism in otherwise non-magnetic 2D materials.

scholarly journals Atomic-Scale Characterization of Metals and Alloys Using Spherical-Aberration Corrected Scanning Transmission Electron Microscopy

2006 ◽  
Vol 12 (S02) ◽  
pp. 1344-1345
Author(s):  
D Williams ◽  
M Watanabe
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Scanning Transmission Electron Microscopy ◽  
Spherical Aberration ◽  
Atomic Scale ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Scale Characterization ◽  
Aberration Corrected

Extended abstract of a paper presented at Microscopy and Microanalysis 2006 in Chicago, Illinois, USA, July 30 – August 3, 2006

Atomic-Scale Imaging and Spectroscopy for In Situ Liquid Scanning Transmission Electron Microscopy

2012 ◽  
Vol 18 (3) ◽  
pp. 621-627 ◽  
Author(s):  
Katherine L. Jungjohann ◽  
James E. Evans ◽  
Jeffery A. Aguiar ◽  
Ilke Arslan ◽  
Nigel D. Browning
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Scanning Transmission Electron Microscopy ◽  
Path Length ◽  
Atomic Scale ◽  
Scanning Transmission Electron ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Aberration Corrected

AbstractObservation of growth, synthesis, dynamics, and electrochemical reactions in the liquid state is an important yet largely unstudied aspect of nanotechnology. The only techniques that can potentially provide the insights necessary to advance our understanding of these mechanisms is simultaneous atomic-scale imaging and quantitative chemical analysis (through spectroscopy) under environmental conditions in the transmission electron microscope. In this study we describe the experimental and technical conditions necessary to obtain electron energy loss (EEL) spectra from a nanoparticle in colloidal suspension using aberration-corrected scanning transmission electron microscopy (STEM) combined with the environmental liquid stage. At a fluid path length below 400 nm, atomic resolution images can be obtained and simultaneous compositional analysis can be achieved. We show that EEL spectroscopy can be used to quantify the total fluid path length around the nanoparticle and demonstrate that characteristic core-loss signals from the suspended nanoparticles can be resolved and analyzed to provide information on the local interfacial chemistry with the surrounding environment. The combined approach using aberration-corrected STEM and EEL spectra with the in situ fluid stage demonstrates a plenary platform for detailed investigations of solution-based catalysis.

scholarly journals Resolving hydrogen atoms at metal-metal hydride interfaces

2020 ◽  
Vol 6 (5) ◽  
pp. eaay4312 ◽  
Author(s):  
Sytze de Graaf ◽  
Jamo Momand ◽  
Christoph Mitterbauer ◽  
Sorin Lazar ◽  
Bart J. Kooi
Keyword(s):  
Metal Hydride ◽  
Phase Contrast ◽  
Scanning Transmission Electron Microscope ◽  
Atomic Scale ◽  
Hydrogen Atoms ◽  
Volumetric Density ◽  
Transmission Electron ◽  
Metal Metal ◽  
Scanning Transmission ◽  
Differential Phase Contrast

Hydrogen as a fuel can be stored safely with high volumetric density in metals. It can, however, also be detrimental to metals, causing embrittlement. Understanding fundamental behavior of hydrogen at the atomic scale is key to improve the properties of metal-metal hydride systems. However, currently, there is no robust technique capable of visualizing hydrogen atoms. Here, we demonstrate that hydrogen atoms can be imaged unprecedentedly with integrated differential phase contrast, a recently developed technique performed in a scanning transmission electron microscope. Images of the titanium-titanium monohydride interface reveal stability of the hydride phase, originating from the interplay between compressive stress and interfacial coherence. We also uncovered, 30 years after three models were proposed, which one describes the position of hydrogen atoms with respect to the interface. Our work enables previously unidentified research on hydrides and is extendable to all materials containing light and heavy elements, including oxides, nitrides, carbides, and borides.

scholarly journals Polyvinylidene fluoride molecules in nanofibers, imaged at atomic scale by aberration corrected electron microscopy

Nanoscale ◽  
2016 ◽  
Vol 8 (1) ◽  
pp. 120-128 ◽  
Author(s):  
Dinesh Lolla ◽  
Joseph Gorse ◽  
Christian Kisielowski ◽  
Jiayuan Miao ◽  
Philip L. Taylor ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Polyvinylidene Fluoride ◽  
Atomic Scale ◽  
Transmission Electron ◽  
Aberration Corrected

Atomic scale twist of polyvinylidene fluoride molecules (PVDF) was observed with aberration corrected transmission electron microscopy.

Sign in / Sign up

Export Citation Format

Share Document