scholarly journals Pseudo-monocrystalline properties of cylindrical nanowires confinedly grown by electrodeposition in nanoporous alumina templates

RSC Advances ◽  
2017 ◽  
Vol 7 (23) ◽  
pp. 13817-13826 ◽  
Author(s):  
Enrique Díaz Barriga-Castro ◽  
Javier García ◽  
Raquel Mendoza-Reséndez ◽  
Víctor M. Prida ◽  
Carlos Luna

Four different cylindrical nanowires systems with single-crystal-like properties have been characterized by transmission electron microscopy and selected area electron diffraction (SAED) under different tilting angles.

2011 ◽  
Vol 189-193 ◽  
pp. 1036-1039
Author(s):  
Jing Ling Ma ◽  
Jiu Ba Wen ◽  
Yan Fu Yan

The precipitates of Al-5Zn-0.02In-1Mg-0.05Ti-0.5Ce (wt %) anode alloy were studied by scanning electron microscopy, X-ray microanalysis, high resolution transmission electron microscopy and selected area electron diffraction analyses in the present work. The results show that the alloy mainly contains hexagonal structure MgZn2 and tetragonal structure Al2CeZn2 precipitates. From high resolution transmission electron microscopy and selected area electron diffraction, aluminium, Al2CeZn2 and MgZn2 phases have [0 1 -1]Al|| [1 -10]Al2CeZn2|| [-1 1 0 1]MgZn2orientation relation, and Al2CeZn2 and MgZn2 phases have the [0 2 -1]Al2CeZn2|| [0 1 -10]MgZn2orientation relation.


1998 ◽  
Vol 553 ◽  
Author(s):  
C. Reich ◽  
M. Conrad ◽  
F. Krumeich ◽  
B. Harbrecht

AbstractThe dodecagonal (dd) quasicrystalline tantalum telluride dd Ta1.6Te and the crystalline approximant Ta97Te60 have been modified by partly replacing tantalum by vanadium. The impact of the substitution on the structures has been studied by X-ray and electron diffraction and by high-resolution transmission electron microscopy. The layered-type approximant structure of Ta83V14Te60 was determined by single crystal X-ray means. The partitioning of vanadium on 21 out of 29 crystallographically inequivalent metal sites is referred to, but not controlled by the Dirichlet domain volume available at the sites. A HRTEM projection of dd (Ta, V)1.6Te onto the dodecagonal plane is analysed with respect to the arrangement of (Ta, V)151Te74 clusters on the vertices of an irregular aperiodic square-triangle tiling, the edge length of which corresponds to the distance between the centres of two such clusters. The clusters comprise about 1 nm thick corrugated lamellae which are periodically stacked by weak Te-Te interactions.


2018 ◽  
Vol 90 (5) ◽  
pp. 833-844
Author(s):  
Leonid Aslanov ◽  
Valery Zakharov ◽  
Ksenia Paseshnichenko ◽  
Aleksandr Yatsenko ◽  
Andrey Orekhov ◽  
...  

AbstractA new method for synthesis of 2D nanocrystals in water was proposed. The use of perfluorothiophenolate ions as surfactant allowed us to produce 2D single-crystal nanosheets of CaS at pH=9 and flat nanocrystals of PbS at pH=9 at room temperature. Mesocrystalline nanobelts of CdS and mesocrystals of PbS were obtained at pH=3–5 and pH=10–12, respectively. Morphology, structure and chemical composition of nanoparticles were characterized by high-resolution transmission electron microscopy, electron diffraction and energy dispersive X-ray spectroscopy. A mechanism of nanoparticles formation was discussed.


1985 ◽  
Vol 49 (352) ◽  
pp. 375-386 ◽  
Author(s):  
C. D. Curtis ◽  
C. R. Hughes ◽  
J. A. Whiteman ◽  
C. K. Whittle

AbstractA range of authigenic sedimentary chlorites from sandstones has been studied by analytical transmission electron microscopy. Selected area (single crystal) electron diffraction patterns are of the Ib (β = 90°) polytype confirming the earlier observations of Hayes (1970).TEM analyses show all samples to be relatively rich in both Al and Fe. In the general formula (Mg,Fe,Al)n [Si8−xAlxO20](OH)16, x varies between 1.5 and 2.6; Fe/(Fe + Mg) between 0.47 and 0.83 and n between 10.80 and 11.54. Octahedral Al is close to 3 in this formulation and Fe2+ predominates over Fe3+. Swelling chlorites have significantly different compositions which are consistent with smectite/chlorite interstratifications.The Ib (β = 90°) polytype appears to be stable under conditions of moderate to deep burial. It replaces berthierine and swelling chlorites formed at lower temperatures. As commonly seen in grain coatings, however, it precipitates from porewater; solutes probably being contributed from several mineral decomposition reactions.


Author(s):  
Frank E. Wawner ◽  
Kenneth R. Lawless

Thin single crystal films of high purity titanium were needed in our laboratory for investigations of the early stages of the oxidation of titanium. Experiments were carried out to determine the feasibility of preparing single crystal titanium films of different orientations by evaporation onto the (100), (110) and (111) surfaces of rocksalt. The structures of these films were investigated by transmission electron microscopy and electron diffraction.


2005 ◽  
Vol 475-479 ◽  
pp. 3575-3578
Author(s):  
Zhi Zhong Dong ◽  
Haiyong Gao ◽  
Cheng Shan Xue ◽  
Zhi Hua Dong ◽  
Jian Ting He

Heagonal GaN nanorods have been synthesized through ammoniating ZnO/Ga2O3 films deposited by radio frequency(rf) magnetron sputtering on Si(111) substrates.X-ray diffraction(XRD), Fourier transform infrared spectrophotometer (FTIR), transimission electron microscopy(TEM), high-resolution transmission electron microscopy(HRTEM) and selected-area electron diffraction (SAED) are used to analyze the structure,composition and morphology of the synthesized GaN nanorods. TEM result shows that GaN nanorods own bamboo-shaped morphalogy and have a single-crystal hexagonal wurtzite structure.The average length and dimeter of the nanorods are 3μm and 50 nm espectively.Ga2O3 and NH3 reactived directly and synthesized GaN nanorods without any catalyzer and the process of space-confined reactions.


2010 ◽  
Vol 152-153 ◽  
pp. 1222-1226
Author(s):  
Yong Gang Wang ◽  
Lin Lin Yang ◽  
Yu Jiang Wang ◽  
Xiao Feng Wang ◽  
Gao Rong Han

Single-crystal PbTiO3 nanoflakes have been synthesized successfully by a hydrothermal method. The as-prepared powders were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), and selected area electron diffraction (SAED). It was found that KOH concentration played a key role in the growth of single-crystal tetragonal perovskite PbTiO3 nanoflakes, and the morphology of PbTiO3 crystallites can be controlled by adjusting the KOH concentration.


1989 ◽  
Vol 169 ◽  
Author(s):  
D. J. Werder ◽  
C. H. Chen ◽  
M. Gurvitch ◽  
B. Miller ◽  
L. F. Schneemeyer ◽  
...  

AbstractWe find by transmission electron diffraction (TED) that the orthorhombic splitting of the upper surface layers (< 1 μm) of single crystal Ba2YCu3O7-δ(YBCO) is reduced, differing by 10 to 30 percent from the bulk value. We also find by transmission electron microscopy (TEM) that in general the surfaces are of inferior quality, and thus, not representative of the bulk. These results have important consequences for those experiments that probe only the upper surface layers. By etching with either Br/ethanol or HClO4/NaClO4 the poor quality surfaces can be removed.


2004 ◽  
Vol 03 (06) ◽  
pp. 891-896
Author(s):  
J. M. ZHU ◽  
S. S. HUANG ◽  
G. B. MA ◽  
X. H. ZHU ◽  
S. H. ZHOU ◽  
...  

Rutile TiO 2 nanorods have been successfully prepared by a sonochemical method. The microstructures of TiO 2 nanorods were investigated in detail by transmission electron microscopy (TEM), selected area electron diffraction (SAED) and high-resolution transmission electron microscopy (HREM). Probable mechanisms for the sonochemical formation of TiO 2 nanorods are proposed.


2012 ◽  
Vol 46 (1) ◽  
pp. 43-47 ◽  
Author(s):  
Wentao Hu ◽  
Shaocun Liu ◽  
Bin Wen ◽  
Jianyong Xiang ◽  
Fusheng Wen ◽  
...  

Twinning structures in ordered nonstoichiometric ZrC0.6have been investigated experimentally and theoretically.Viatransmission electron microscopy and selected area electron diffraction measurements, {111}-specific twins have been observed. Interestingly, two special types of twinning interfaces,i.e.(111)Cand (111)Zrinterfaces, are recognized to be formed as a result of the presence of ordered carbon vacancies. In contrast to the high stacking fault energy for twinning formation in stoichiometric ZrC, first-principles calculations indicate that the presence of ordered carbon vacancies leads to a great reduction in the twinning interfacial energy, thus favouring the stabilization of twinning structures in the ordered ZrC0.6.


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