scholarly journals Synthesis of Co Filled Carbon Nanotubes by In Situ Reduction of CoCl2 Filled Nanotubes by NaBH4

2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
J. Mittal

An alternative process of filling the multiwall nanotubes (MWCNTs) with cobalt metal was developed. Empty core of nanotubes was first filled with CoCl2 by stirring with CoCl2 and alcohol at room temperature for six hours. CoCl2 filling inside MWCNTs was then converted into Co after treating with NaBH4 at room temperature. High resolution transmission electron microscope (HRTEM) studies showed the filling of the CoCl2 and Co inside the nanotubes before and after the treatment. EDX studies show the nonexistence of chlorine after the reduction with NaBH4. Amount of filling was also reduced after the treatment. Paper describes the possible mechanism of filling CoCl2 inside nanotube and its reduction by NaBH4.

Alloys of Al-5% Pb and Al-5% Pb-0.5% Si (by mass) have been manufactured by rapid solidification and then examined by transmission electron microscopy. The rapidly solidified alloy microstructures consist of 5-60 nm Pb particles embedded in an Al matrix. The Pb particles have a cube-cube orientation relation with the Al matrix, and are cub-octahedral in shape, bounded by {100} Al, Pb and {111} Al, Pb facets. The equilibrium Pb particle shape and therefore the anisotropy of solid Al-solid Pb and solid Al-liquid Pb surface energies have been monitored by in situ heating in the transmission electron microscope over the temperature range between room temperature and 550°C. The ani­sotropy of solid Al-solid Pb surface energy is constant between room temperature and the Pb melting point, with a {100} Al, Pb surface energy about 14% greater than the {111} Al, Pb surface energy, in good agreement with geometric near-neighbour bond energy calculations. The {100} AI, Pb facet disappears when the Pb particles melt, and the anisotropy of solid Al-liquid Pb surface energy decreases gradually with increasing temperature above the Pb melting point, until the Pb particles become spherical at about 550°C.


2006 ◽  
Vol 88 (12) ◽  
pp. 123101 ◽  
Author(s):  
D. Golberg ◽  
M. Mitome ◽  
K. Kurashima ◽  
C. Y. Zhi ◽  
C. C. Tang ◽  
...  

2008 ◽  
Vol 8 (11) ◽  
pp. 5878-5886 ◽  
Author(s):  
Jun Wang ◽  
Stephen J. Sollenberger ◽  
Ying Yuan ◽  
Timothy J. Yosenick ◽  
James H. Adair

Silica coated CdS tabular nanocomposites were synthesized through precipitation of CdS nanoparticles in octylamine/water bilayer system followed by in situ hydrolysis of tetraethoxylsilicate (TEOS) precursor. Face diameter of the nanoplatelets was in the range of 50∼250 nm with a variable thickness (3 to 25 nm) dictated by octylamine content or R ratio ([water]/[octylamine]). A uniform SiO2 outer shell of about 15 nm was observed regardless of the size of the high aspect ratio CdS nanoplatelets, which appeared to be agglomerated primarily owing to the confined bilayer template. Morphology and microstructure of the CdS/SiO2 tabular nanocomposites were characterized using atomic force microscope (AFM) and high resolution transmission electron microscope (HRTEM). A noticeable enhancement in absorbance for the UV-vis spectra was observed due to the SiO2 coating layer. Growth mechanism of nanocomposite platelets and potential applications associated with this anisotropic nanocomposite are discussed.


Nanoscale ◽  
2018 ◽  
Vol 10 (17) ◽  
pp. 7978-7983 ◽  
Author(s):  
Liang Cheng ◽  
Xianfang Zhu ◽  
Jiangbin Su

The coalescence of two single-crystalline Au nanoparticles on surface of amorphous SiOxnanowire, as induced by electron beam irradiation, wasin situstudied at room temperature in a transmission electron microscope.


2000 ◽  
Vol 650 ◽  
Author(s):  
A. Meldrum ◽  
K. Beaty ◽  
L. A. Boatner ◽  
C. W. White

ABSTRACTIrradiation-induced amorphization of Cd2Nb2O7 pyrochlore was investigated by means of in-situ temperature-dependent ion-irradiation experiments in a transmission electron microscope, combined with ex-situ ion-implantation (at ambient temperature) and RBS/channeling analysis. The in-situ experiments were performed using Ne or Xe ions with energies of 280 and 1200 keV, respectively. For the bulk implantation experiments, the incident ion energies were 70 keV (Ne+) and 320 keV (Xe2+). The critical amorphization temperature for Cd2Nb2O7 is ∼480 K (280 keV Ne+) or ∼620 K (1200 keV Xe2+). The dose for in-situ amorphization at room temperature is 0.22 dpa for Xe2+, but is 0.65 dpa for Ne+ irradiation. Both types of experiments suggest a cascade overlap mechanism of amorphization. The results were analyzed in light of available models for the crystalline-to-amorphous transformation and were compared to previous ionirradiation experiments on other pyrochlore compositions.


2D Materials ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 031001
Author(s):  
Simon Hettler ◽  
David Sebastian ◽  
Mario Pelaez-Fernandez ◽  
Ana M Benito ◽  
Wolfgang K Maser ◽  
...  

2004 ◽  
Vol 19 (10) ◽  
pp. 3062-3067 ◽  
Author(s):  
Haiping Sun ◽  
Xiaoqing Pan

When exposed to air at room temperature, Zn nanoparticles oxidize gradually to form crystalline ZnO shells with a thickness of a few nanometers. Electron diffraction and high-resolution lattice imaging revealed that the ZnO layer on the Zn {0001} surface is composed of many epitaxial domains with small rotation angles relative to the lattice of the Zn core. The oxidized Zn particle bends when irradiated by the electron beam in a transmission electron microscope. This is due to the increase of internal stress in the ZnO layer as a result of the realignment of adjacent domains under electron beam irradiation. Corrosion of Zn nanoparticles was observed and the scaling and spalling start to occur on the {1010} prismatic faces.


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