scholarly journals Probing the dynamics of nanoparticle formation from a precursor at atomic resolution

2019 ◽  
Vol 5 (1) ◽  
pp. eaau9590 ◽  
Author(s):  
Wenpei Gao ◽  
Peter Tieu ◽  
Christopher Addiego ◽  
Yanling Ma ◽  
Jianbo Wu ◽  
...  

Control of reduction kinetics and nucleation processes is key in materials synthesis. However, understanding of the reduction dynamics in the initial stages is limited by the difficulty of imaging chemical reactions at the atomic scale; the chemical precursors are prone to reduction by the electron beams needed to achieve atomic resolution. Here, we study the reduction of a solid-state Pt precursor compound in an aberration-corrected transmission electron microscope by combining low-dose and in situ imaging. The beam-sensitive Pt precursor, K2PtCl4, is imaged at atomic resolution, enabling determination of individual (K, Pt, Cl) atoms. The transformation to Pt nanoclusters is captured in real time, showing a three-stage reaction including the breaking of the ionic bond, formation of PtCl2, and the reduction of the dual-valent Pt to Pt metal. Deciphering the atomic-scale transformation of chemicals in real time using combined low-dose and in situ imaging brings new possibility to study reaction kinetics in general.

Nanoscale ◽  
2017 ◽  
Vol 9 (34) ◽  
pp. 12479-12485
Author(s):  
Xing Huang ◽  
Travis Jones ◽  
Hua Fan ◽  
Marc-Georg Willinger

Void formation and anisotropic growth in ZnS ribbons have been studied by in situ transmission electron microscopy.


Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 163
Author(s):  
Iryna Zelenina ◽  
Igor Veremchuk ◽  
Yuri Grin ◽  
Paul Simon

Nano-scaled thermoelectric materials attract significant interest due to their improved physical properties as compared to bulk materials. Well-shaped nanoparticles such as nano-bars and nano-cubes were observed in the known thermoelectric material PbTe. Their extended two-dimensional nano-layer arrangements form directly in situ through electron-beam treatment in the transmission electron microscope. The experiments show the atomistic depletion mechanism of the initial crystal and the recrystallization of PbTe nanoparticles out of the microparticles due to the local atomic-scale transport via the gas phase beyond a threshold current density of the beam.


2021 ◽  
Vol 10 (3) ◽  
pp. 578-586
Author(s):  
Lin-Kun Shi ◽  
Xiaobing Zhou ◽  
Jian-Qing Dai ◽  
Ke Chen ◽  
Zhengren Huang ◽  
...  

AbstractA nano-laminated Y3Si2C2 ceramic material was successfully synthesized via an in situ reaction between YH2 and SiC using spark plasma sintering technology. A MAX phase-like ternary layered structure of Y3Si2C2 was observed at the atomic-scale by high resolution transmission electron microscopy. The lattice parameters calculated from both X-ray diffraction and selected area electron diffraction patterns are in good agreement with the reported theoretical results. The nano-laminated fracture of kink boundaries, delamination, and slipping were observed at the tip of the Vickers indents. The elastic modulus and Vickers hardness of Y3Si2C2 ceramics (with 5.5 wt% Y2O3) sintered at 1500 °C were 156 and 6.4 GPa, respectively. The corresponding values of thermal and electrical conductivity were 13.7 W·m-1·K-1 and 6.3×105 S·m-1, respectively.


2008 ◽  
Vol 1142 ◽  
Author(s):  
Hideto Yoshida ◽  
Seiji Takeda ◽  
Tetsuya Uchiyama ◽  
Hideo Kohno ◽  
Yoshikazu Homma

ABSTRACTNucleation and growth processes of carbon nanotubes (CNTs) in iron catalyzed chemical vapor deposition (CVD) have been observed by means of in-situ environmental transmission electron microscopy. Our atomic scale observations demonstrate that solid state iron carbide (Fe3C) nanoparticles act as catalyst for the CVD growth of CNTs. Iron carbide nanoparticles are structurally fluctuated in CVD condition. Growth of CNTs can be simply explained by bulk diffusion of carbon atoms since nanoparticles are carbide.


2008 ◽  
Vol 14 (S2) ◽  
pp. 436-437 ◽  
Author(s):  
G Yang ◽  
Y Zhao ◽  
K Sader ◽  
A Bleloch ◽  
RF Klie

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008


2020 ◽  
Author(s):  
Chongjun Jin ◽  
Nicholas Fang ◽  
Xiaoyi She ◽  
Huifeng Du ◽  
Yang Shen ◽  
...  

Abstract Visualizing hydrogenation processes in metals in real-time is important to various hydrogen-involved applications. However, observing hydrogen diffusion was limited by transmission electron microscopy, and the kinetics of hydrogenation in the interior of the metals was not reported. Here we proposed an optical microscopy-based visualization of palladium hydrogenation from diffusion surface to the interior by introducing a fast-response mechanical platform that transforms the hydrogen diffusion into self-organized ordered wrinkles with sharp optical contrast. This platform is an Au/Pd double layer on elastomer which results in directional hydrogenation from sidewall to the interior. The kinetics of hydrogenation in the interior of the palladium along the diffusion direction was monitored in real-time. This platform will enable in-situ visualization of atom/ion diffusion on metals that are crucial in energy storage and hydrogen detection.


2021 ◽  
Vol 9 ◽  
Author(s):  
Jenna L. Wardini ◽  
Hasti Vahidi ◽  
Huiming Guo ◽  
William J. Bowman

Transmission electron microscopy (TEM), and its counterpart, scanning TEM (STEM), are powerful materials characterization tools capable of probing crystal structure, composition, charge distribution, electronic structure, and bonding down to the atomic scale. Recent (S)TEM instrumentation developments such as electron beam aberration-correction as well as faster and more efficient signal detection systems have given rise to new and more powerful experimental methods, some of which (e.g., 4D-STEM, spectrum-imaging, in situ/operando (S)TEM)) facilitate the capture of high-dimensional datasets that contain spatially-resolved structural, spectroscopic, time- and/or stimulus-dependent information across the sub-angstrom to several micrometer length scale. Thus, through the variety of analysis methods available in the modern (S)TEM and its continual development towards high-dimensional data capture, it is well-suited to the challenge of characterizing isometric mixed-metal oxides such as pyrochlores, fluorites, and other complex oxides that reside on a continuum of chemical and spatial ordering. In this review, we present a suite of imaging and diffraction (S)TEM techniques that are uniquely suited to probe the many types, length-scales, and degrees of disorder in complex oxides, with a focus on disorder common to pyrochlores, fluorites and the expansive library of intermediate structures they may adopt. The application of these techniques to various complex oxides will be reviewed to demonstrate their capabilities and limitations in resolving the continuum of structural and chemical ordering in these systems.


Author(s):  
Andreas Thust ◽  
Juri Barthel ◽  
Karsten Tillmann

The FEI Titan 80-300 TEM is a high-resolution transmission electron microscope equipped with a field emission gun and a corrector for the spherical aberration (<em>C</em><sub>S</sub>) of the imaging lens system. The instrument is designed for the investigation of a wide range of solid state phenomena taking place on the atomic scale, which requires true atomic resolution capabilities. Under optimum optical settings of the image <em>C</em><sub>S</sub>-corrector (CEOS CETCOR) the point-resolution is extended up to the information limit of well below 100 pm with 200 keV and 300 keV electrons. A special piezo-stage design allows ultra-precise positioning of the specimen in all 3 dimensions. Digital images are acquired with a Gatan 2k x 2k slow-scan charged coupled device camera.


Sign in / Sign up

Export Citation Format

Share Document