Can we trust TEM images of silicate glasses?

2003 ◽  
Vol 792 ◽  
Author(s):  
Nan Jiang
Keyword(s):  
Electron Microscopy ◽  
Phase Separation ◽  
Electron Irradiation ◽  
Driving Force ◽  
Silicate Glasses ◽  
Nano Particles ◽  
Nano Particle ◽  
Transmission Electron ◽  
Poor Region

ABSTRACTElectron irradiation-induced modifications in two glasses, K2O – SiO2 and Au doped Na2O – B2O3 – SiO2, were observed in electron microscope. The products of modifications were “nano-particle” like contrasts in transmission electron microscopy (TEM) images, which can be easily confused with real nano-particles and phase separation. The driving force for the modifications in the glasses is the tendency of elimination of non-bridging oxygen (NBO) through the removal of cations. The phase separation into cation rich and poor region is their nature under electron irradiation. Therefore, it is absolutely essential to record in situ frames when the TEM images are used to provide microstructure information of glasses. Additionally, charging effects in glasses have also been discussed.

Preparation of High-Rigidity, High-Toughness Unplasticized Poly(vinyl Chloride) for Plastic Windows Profiles Reinforced and Toughened by Nano-CaCO3

2011 ◽  
Vol 71-78 ◽  
pp. 1237-1241
Author(s):  
Ming Shan Yang ◽  
Lin Kai Li
Keyword(s):  
Electron Microscopy ◽  
Vinyl Chloride ◽  
Sem Analysis ◽  
Nano Particles ◽  
Inorganic Complex ◽  
Poly Vinyl Chloride ◽  
Transmission Electron ◽  
Large Fiber ◽  
Acrylate Polymer

The organic-inorganic complex nano-particles with core-shell structure were synthesized by in situ emulsion polymerization based on fresh slush pulp of calcium carbonate (CaCO3) nanoparticles and acrylate polymer in this paper. The dispersion and encapsulation of nanoparticles were investigated by transmission electron microscopy (TEM). Unplasticized poly(vinyl chloride)(UPVC) was modified by organic-inorganic complex nanoparticles and the effects of toughening and reinforcing were systematically studied. The results showed that the effects of the reinforcement and toughening of organic-inorganic complex nanoparticles on UPVC were very significant. Especially, scanning electron microscopy(SEM) analysis results indicated that large-fiber drawing and network morphologies coexisted in the system of UPVC by joint modification of nanoparticles with CPE.

scholarly journals Chemical trigger toward phase separation in the aqueous Al(III) system revealed

2020 ◽  
Vol 6 (23) ◽  
pp. eaba6878
Author(s):  
Miodrag J. Lukić ◽  
Eduard Wiedenbeck ◽  
Holger Reiner ◽  
Denis Gebauer
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Nuclear Magnetic Resonance ◽  
Phase Separation ◽  
High Resolution ◽  
Driving Force ◽  
Crystallization Process ◽  
Resonance Spectroscopy ◽  
Chemical Behavior ◽  
Transmission Electron

Although Al(III) hydrolysis, condensation, and nucleation play pivotal roles in the synthesis of Al-based compounds and determine their chemical behavior, we still lack experimental evidence regarding the chemistry of nucleation from solution. Here, by combining advanced titration assays, high-resolution transmission electron microscopy (HR-TEM), and 27Al–nuclear magnetic resonance spectroscopy, we show that highly dynamic solute prenucleation clusters (PNCs) are fundamental precursors of nanosolid formation. Chemical changes from olation to oxolation bridging within PNCs rely on the formation of tetrahedral AlO4 in solution and trigger phase separation at low driving force (supersaturation). This does not include the formation of Keggin-Al13 ions, at least during the earliest stages. The PNC pathway of the formation of Al(III) (oxy)(hydr)oxides offers new possibilities toward the development of strategies for controlling the entire crystallization process.

scholarly journals In situ Transmission Electron Microscopy on the Conductance Quantization of a Fe Nano-particle System

Materia Japan ◽  
2005 ◽  
Vol 44 (12) ◽  
pp. 990-990
Author(s):  
Ryusuke Hirose ◽  
Masashi Arita ◽  
Kouichi Hamada ◽  
Yasuo Takahashi
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Particle System ◽  
Nano Particle ◽  
Conductance Quantization ◽  
Transmission Electron

scholarly journals Effect of High-Density Nanoparticles on Recrystallization and Texture Evolution in Ferritic Alloys

Crystals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 172 ◽  
Author(s):  
Eda Aydogan ◽  
Connor Rietema ◽  
Ursula Carvajal-Nunez ◽  
Sven Vogel ◽  
Meimei Li ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Texture Evolution ◽  
Fiber Texture ◽  
High Density ◽  
Nano Particles ◽  
Ferritic Alloys ◽  
Fecral Alloy ◽  
Transmission Electron

Ferritic alloys are important for nuclear reactor applications due to their microstructural stability, corrosion resistance, and favorable mechanical properties. Nanostructured ferritic alloys having a high density of Y-Ti-O rich nano-oxides (NOs < 5 nm) are found to be extremely stable at high temperatures up to ~1100 °C. This study serves to understand the effect of a high density of nano-particles on texture evolution and recrystallization mechanisms in ferritic alloys of 14YWT (14Cr-3W-0.4Ti-0.21Y-Fe wt %) having a high density of nano-particles and dispersion-free FeCrAl (13Cr-5.2Al-0.05Y-2Mo-0.2Si-1Nb wt %). In order to investigate the recrystallization mechanisms in these alloys, neutron diffraction, electron backscattered diffraction, and in situ and ex situ transmission electron microscopy have been utilized. It has been observed that even though the deformation textures of both the 14YWT and FeCrAl alloys evolved similarly, resulting in either the formation (in FeCrAl alloy) or increase (in 14YWT) in γ-fiber texture, the texture evolution during recrystallization is different. While FeCrAl alloy keeps its γ-fiber texture after recrystallization, 14YWT samples develop a ε-fiber as a result of annealing at 1100 °C, which can be attributed to the existence of NOs. In situ transmission electron microscopy annealing experiments on 14YWT show the combination and growth of the lamellar grains rather than nucleation; however, the recrystallization and growth kinetics are slower due to NOs compared to FeCrAl.

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