Transmission Electron Miscroscopy Observation of the Decomposition of YBa2Cu4O8 into YBa2Cu3O7-δ and CuO

1997 ◽  
Vol 12 (4) ◽  
pp. 906-914 ◽  
Author(s):  
M. Reder ◽  
J. Krelaus ◽  
D. Müller ◽  
K. Heinemann ◽  
H. C. Freyhardt
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Beam ◽  
Critical Current Density ◽  
Flux Pinning ◽  
Starting Material ◽  
Transmission Electron ◽  
Beam Heating ◽  
Electron Beam Heating

The decomposition of Yba2Cu4O8 (Y-124) into Yba2Cu3O7-δ (Y-123) and CuO at high temperatures has been expected to create Y-123 with finely dispersed CuO precipitates suitable for flux pinning. In fact, samples of thermally decomposed Y-124 exhibit a critical current density, Jc, which is enhanced with respect to the starting material as well as to pure Y-123. Transmission electron microscopy (TEM) studies of furnace annealed Y-124 were not suitable to clarify the reason for this Jc enhancement. Nevertheless, the formation and growth of CuO precipitates have been observed by in situ decomposition of the Y-124 starting material due to electron beam heating within the TEM.

Direct Observation of Defect Motion in Silicon By High-Resolution Transmission Electron Microscopy

1985 ◽  
Vol 43 ◽  
pp. 358-359
Author(s):  
M. A. Parker ◽  
R. Sinclair
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Beam ◽  
High Resolution ◽  
Crystal Defects ◽  
Incident Electron Beam ◽  
Transmission Electron ◽  
Heating Effects ◽  
Electron Beam Heating

Observations of defect motion by high resolution transmission electron microscopy (HRTEM) are rare. Unfortunately, the application of this technique has been limited to a few unique materials, those that can obtain sufficient thermal energy for the initiation of atomic motion through the heating effects of the incident electron beam. In earlier work, it was speculated that events such as the motion of crystal defects, observed in cadmium telluride (CdTe) with the electron beam heating method, might become evident in materials such as silicon (Si) if only sufficiently high temperatures could be achieved (∼ 600°C) in-situ.A silicon specimen with a suitable population of defects was chosen for examination; it consisted of a cross-section of.3 μ ﹛100﹜ silicon on ﹛1102﹜ sapphire (SOS from Union Carbide) which was implant amorphized by 28Si+ ion implantation at an energy of ∼ 170keV.

scholarly journals Visualizing Ligand-Mediated Bimetallic Nanocrystal Formation Pathways with In Situ Liquid Phase Transmission Electron Microscopy Synthesis

2020 ◽  
Author(s):  
Mei Wang ◽  
Asher Leff ◽  
Yue Li ◽  
Taylor Woehl
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Beam ◽  
Ex Situ ◽  
Formation Mechanisms ◽  
Transmission Electron ◽  
Thiolate Complexes ◽  
Nanocrystal Formation ◽  
Phase Transmission

Colloidal synthesis of alloyed multimetallic nanocrystals with precise composition control remains a challenge and a critical missing link in theory-driven rational design of functional nanomaterials. Liquid phase transmission electron microscopy (LP-TEM) enables directly visualizing nanocrystal formation mechanisms that can inform discovery of design rules for colloidal multimetallic nanocrystal synthesis, but it remains unclear whether the salient chemistry of the flask synthesis is preserved in the extreme electron beam radiation environment during LPTEM. Here we demonstrate controlled in situ LP-TEM synthesis of alloyed AuCu nanoparticles while maintaining the molecular structure of electron beam sensitive metal thiolate precursor complexes. Ex situ flask synthesis experiments showed that nearly equimolar AuCu alloys formed from heteronuclear metal thiolate complexes, while gold-rich alloys formed in their absence. Systematic dose rate-controlled in situ LP-TEM synthesis experiments established a range of electron beam synthesis conditions that formed alloyed AuCu nanoparticles with similar alloy composition, random alloy structure, and particle size distribution shape as those from ex situ flask synthesis, indicating metal thiolate complexes were preserved under these conditions. Reaction kinetic simulations of radical-ligand reactions revealed that polymer capping ligands acted as effective hydroxyl radical scavengers during LP-TEM synthesis and prevented metal thiolate oxidation at low dose rates. In situ synthesis experiments and ex situ atomic scale imaging revealed that a key role of metal thiolate complexes was to prevent copper atom oxidation and facilitate formation of prenucleation cluster intermediates. This work demonstrates that complex ion precursor chemistry can be maintained during LP-TEM imaging, enabling probing nanocrystal formation mechanisms with LP-TEM under reaction conditions representative of ex situ flask synthesis.

In situ Transmission Electron Microscopy Studies on Structural Dynamics of Transition Metal Nanoclusters

2005 ◽  
Vol 20 (7) ◽  
pp. 1785-1791 ◽  
Author(s):  
T. Vystavel ◽  
S.A. Koch ◽  
G. Palasantzas ◽  
J.Th.M. De Hosson
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Beam ◽  
Transition Metal ◽  
Electron Beam Irradiation ◽  
Oxide Shell ◽  
Metal Nanoclusters ◽  
Beam Irradiation ◽  
Transmission Electron

The structural stability of transition metal nanoclusters has been scrutinized with in situ transmission electron microscopy as a function of temperature. In particular iron, cobalt, niobium, and molybdenum clusters with diameters around 5 nm have been investigated. During exposure to air, a thin oxide shell with a thickness of 2 nm is formed around the iron and cobalt clusters, which is thermally unstable under moderate high vacuum annealing above 200 °C. Interestingly, niobium clusters oxidize only internally at higher temperatures without the formation of an oxide shell. They are unaffected under electron beam irradiation, whereas iron and cobalt undergo severe structural changes. Further, no cluster coalescence of niobium takes place, even during annealing up to 800 °C, whereas iron and cobalt clusters coalesce after decomposition of the oxide, as long as the clusters are in close contact. In contrast to niobium, molybdenum clusters do not oxidize upon annealing; they are stable under electron beam irradiation and coalesce at temperatures higher than 800 °C. In all cases, the coalescence process indicates a strong influence of the local environment of the cluster.

scholarly journals Accessing local electron-beam induced temperature changes during in situ liquid-phase transmission electron microscopy

2021 ◽  
Author(s):  
Birk Fritsch ◽  
Andreas Hutzler ◽  
Mingjian Wu ◽  
Saba Khadivianazar ◽  
Lilian Vogl ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Beam ◽  
Liquid Phase ◽  
Gas Bubble ◽  
Local Electron ◽  
Temperature Changes ◽  
Transmission Electron ◽  
Phase Transmission

Electron-beam induced heating in the vicinity of a gas bubble in liquid-phase TEM is quantified in situ.

scholarly journals In-Situ Transmission Electron Microscopy: Electron Beam Effects in Carbon-based Nanomaterials

2021 ◽  
Vol 27 (S1) ◽  
pp. 2110-2113
Author(s):  
Zhehan Ying ◽  
Jiangyong Diao ◽  
Shi Wang ◽  
Xiangbin Cai ◽  
Hongyang Liu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Beam ◽  
Transmission Electron ◽  
Carbon Based Nanomaterials ◽  
Carbon Based
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