Synthesis of ZnO2 Nanocrystals Produced by Hydrothermal Process

2009 ◽  
Vol 1242 ◽  
Author(s):  
R. Esparza ◽  
A. Aguilar ◽  
A. Escobedo-Morales ◽  
C. Patiño-Carachure ◽  
U. Pal ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Hydrogen Peroxide ◽  
Transmission Electron Microscopy ◽  
Hydrothermal Process ◽  
High Resolution Electron Microscopy ◽  
X Ray ◽  
Transmission Electron ◽  
Resolution Electron ◽  
Zinc Peroxide ◽  
20 Nm

ABSTRACTZinc peroxide (ZnO2) nanocrystals were directly produced by hydrothermal process. The nanocrystals were synthesized using zinc acetate as precursor and hydrogen peroxide as oxidant agent. The ZnO2 powders were characterized by X-ray powder diffraction and transmission electron microscopy. The results of transmission electron microscopy indicated that the ZnO2powders consisted of nanocrystals with diameters below to 20 nm and a faceted morphology. High resolution electron microscopy observations have been used in order to the structural characterization. ZnO2 nanocrystals exhibit a well-crystallized structure.

Phase Diagram Determination For Modifications Of The D Phase In The Al-AlCo-AINi System

1998 ◽  
Vol 553 ◽  
Author(s):  
R. Lück ◽  
M. Scheffer ◽  
T. Gödecke ◽  
S. Ritschj ◽  
C. Beelif
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Liquidus Projection ◽  
High Resolution Electron Microscopy ◽  
Reaction Scheme ◽  
Decagonal Phase ◽  
Transmission Electron ◽  
Resolution Electron ◽  
In Situ Experiments ◽  
Projection Surface

AbstractAn extensive investigation into the At-AICo-AlNi ternary subsystem is presented. Observations have used the techniques of differential thermal analysis, magnetothermal analysis, dilatometry, metallography, X-ray diffraction, transmission electron microscopy, and high-resolution electron microscopy. Representative graphic documentation, as liquidus projection surface, isothermal sections, temperature-concentration section, and reaction scheme are presented. 11 phases from the binaries Al-Co and Al-Ni and the three ternary phases Y2 (Co2NiAl9), X and the decagonal phase D were found at room temperature. The decagonal phase is formed from the melt peritectically via a critical tie line and its primary formation area dominates at the liquidus projection surface. 45 three-phase regions are present according to the reaction scheme.Several phase variants in the area of the decagonal phase were detected by transmission electron microscopy. Phase fields of the variants were determined from samples quenched from their respective temperatures. In-situ experiments on transformations of variants were performed by dilatometric measurements. The subdivision of the D phase area into the fields of the variants is discussed.

Synthesis and Magnetic Properties of CoFe2O4 Nano-Particles

2010 ◽  
Vol 148-149 ◽  
pp. 998-1002 ◽  
Author(s):  
Xiao Yun Chen ◽  
Hua Li ◽  
Yue Zeng Su ◽  
Zi Shan Huang ◽  
He Zhou Liu
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Magnetic Properties ◽  
Hydrothermal Process ◽  
Nano Particles ◽  
Vibrating Sample Magnetometer ◽  
X Ray ◽  
Transmission Electron ◽  
Structure Morphology ◽  
Water Ratio

Spinel CoFe2O4 nano-particles were synthesized by hydrothermal traditionally and Ethylene Glycol (EG) assisted hydrothermal process originally. The effects of reaction temperatures from 140°C to 200°C, different OH- provider and EG/water ratio on the nano-particles’ structure, morphology and magnetic properties of composition were studied by X-ray diffractometer (XRD), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). The possible mechanism for the effects on the properties was also discussed in details. The results showed that NaAC as OH- provider and higher EG/water ratio in solvent were benefit for getting smaller CoFe2O4 nano-particles. And existence of EG is also important to remove the α-Fe2O3 phase.

A transmission electron microscopy study of the crystallinity and secondary phase formation in melt-processed YBa2Cu3O7−δ

1996 ◽  
Vol 11 (12) ◽  
pp. 2990-2999 ◽  
Author(s):  
Y. Yan ◽  
D. A. Cardwell ◽  
A. M. Campbell ◽  
W. M. Stobbs
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Secondary Phase ◽  
High Resolution Electron Microscopy ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Transmission Electron ◽  
Resolution Electron ◽  
Secondary Phase Formation ◽  
Layer Stacking

The microstructure of large grain melt-processed YBa2Cu3O7−δ containing 10 molar% excess Y2BaCuO5 prepared and oxygenated under atmospheric pressure has been investigated by transmission electron microscopy (TEM) and optical microscopy. These materials always contain parallel structural and microscopic platelet-like features in the crystallographic a-b plane of a few microns spacing which have been variously described as grain boundaries or microcracks. We have observed such features, which clearly influence the flow of current in melt-processed YBCO, to consist of copper deficient, impurity phase material which can be either amorphous or crystalline in nature. A variety of defects have been observed by high-resolution electron microscopy (HREM) in the vicinity of these platelet boundaries, including double and triple CuO layer stacking faults, which may constitute effective flux pinning sites.

High Resolution Transmission Electron Microscopy of Partial States of Oxygen Order in YBa2Cu3Oz

1990 ◽  
Vol 183 ◽  
Author(s):  
C. P. Burmester ◽  
S. Quong ◽  
L. T. Wille ◽  
R. Gronsky ◽  
B. T. Ahn ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
High Resolution Electron Microscopy ◽  
Contrast Effects ◽  
Oxygen Loss ◽  
Transmission Electron ◽  
Resolution Electron ◽  
Out Of Plane ◽  
Partial States

AbstractHigh resolution electron microscopy is used to investigate the effect of electron irradiation induced oxygen loss on the states of partial order in YBa2Cu3Oz. Contrast effects visible in the [001] zone image as a result of the degree of the out-of-plane correlation of these ordered states are investigated. Using statistical simulations to aid in the analysis of the HREM images, an interpretation based on a kinetically limited evolution of the variation of long range [001] ordering is proposed.

Transmission electron microscopy study of Co/Pd and Co/Au multilayers

1993 ◽  
Vol 8 (5) ◽  
pp. 1019-1027 ◽  
Author(s):  
F. Hakkens ◽  
A. De Veirman ◽  
W. Coene ◽  
Broeder F.J.A. den
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
High Resolution Electron Microscopy ◽  
Microscopy Study ◽  
Columnar Structure ◽  
Electron Microscopy Study ◽  
Misfit Dislocations ◽  
Transmission Electron ◽  
Resolution Electron

The structure of Co/Pd and Co/Au (111) multilayers is studied using transmission electron microscopy and high resolution electron microscopy. We focused on microstructure, atomic stacking (especially at the interfaces), and coherency, as these are structural properties that have considerable magnetic effects. A columnar structure with a strong curvature of the multilayer influenced by substrate temperature during growth is observed. High resolution imaging shows numerous steps at the interfaces of the multilayer structure and the presence of misfit dislocations. In bright-field images, periodic contrast fringes are observed at these interfaces as the result of moiré interference. These moiré fringes are used to study the misfit relaxation at the interfaces, whereas electron diffraction gives the average relaxation over the whole layer. Both measurements determined that, for Co/Pd as well as Co/Au multilayers, 80–85% of the misfit is relaxed and 20–15% remains in the form of strain, independent of the Co layer thickness in the regime studied.

Hydrothermal Synthesis of Zn2(MoO4)(SeO3) and Photocatalytic Applications

2013 ◽  
Vol 385-386 ◽  
pp. 16-18
Author(s):  
Yan Zhong Zhen ◽  
Dan Jun Wang ◽  
Feng Fu ◽  
Gang Lin Xue
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Hydrothermal Synthesis ◽  
Hydrothermal Process ◽  
Experimental Result ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Photocatalytic Applications ◽  
Simple Hydrothermal Process

A novel mixed metal molybdates, Zn2(MoO4)(SeO3) 1 has been synthesized by a simple hydrothermal process. Samples obtained are characterized using powder and single crystal X-ray diffraction (XRD), transmission electron microscopy (TEM). Furthermore, the photocatalytic performances of samples obtained are investigated for degradation of RhB under visible light irradiation. photocayalysis experimental result has illustrated that the compound exhibits good photocatalysis.

Dissolution of Copper Precipitates in An Fe−1·3Wt%Cu Alloy Under Fe+ Ion Irradiation

1998 ◽  
Vol 540 ◽  
Author(s):  
A. C. Nicol ◽  
M. L. Jenkins ◽  
N. Wanderka ◽  
C. Abromeit
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Room Temperature ◽  
Ion Irradiation ◽  
High Resolution Electron Microscopy ◽  
Cu Alloy ◽  
Transmission Electron ◽  
Resolution Electron ◽  
The Stability

AbstractThe stability of Cu precipitates in an Fe-1.3wt%Cu alloy under 300 keV Fe+ion irradiation has been investigated using transmission electron microscopy and high-resolution electron microscopy. The irradiations were carried out between room temperature and 550°C at displacement rates of 103 to 10−2 dpa(s)−1 to fluences of up to 30 dpa. Copper precipitates were found to keep their shape but decrease in size under all irradiation conditions. The results are discussed within the framework of a competitive process between irradiation induced ballistic destruction of precipitates by cascades and irradiation-enhanced precipitation.

Grain Boundary Transformations in Bi-Doped Copper

1991 ◽  
Vol 238 ◽  
Author(s):  
Elsie C. Urdaneta ◽  
David E. Luzzi ◽  
Charles J. McMahon
Keyword(s):  
Electron Microscopy ◽  
Heat Treatment ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Treatment Time ◽  
High Resolution Electron Microscopy ◽  
Transmission Electron ◽  
Resolution Electron

ABSTRACTBismuth-induced grain boundary faceting in Cu-12 at ppm Bi polycrystals was studied using transmission electron microscopy (TEM). The population of faceted grain boundaries in samples aged at 600°C was observed to increase with heat treatment time from 15min to 24h; aging for 72h resulted in de-faceting, presumably due to loss of Bi from the specimen. The majority of completely faceted boundaries were found between grains with misorientation Σ=3. About 65% of the facets of these boundaries were found to lie parallel to crystal plane pairs of the type {111}1/{111]2- The significance of these findings in light of recent high resolution electron microscopy experiments is discussed.

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