Direct in situ observation of ZnO nucleation and growth via transmission X-ray microscopy

Nanoscale ◽  
2016 ◽  
Vol 8 (4) ◽  
pp. 1849-1853 ◽  
Author(s):  
S. E. R. Tay ◽  
A. E. Goode ◽  
J. Nelson Weker ◽  
A. A. Cruickshank ◽  
S. Heutz ◽  
...  

The nucleation and growth of a nanostructure controls its size and morphology, and ultimately its functional properties.

2015 ◽  
Vol 55 (7) ◽  
pp. 1474-1482 ◽  
Author(s):  
Dowon Seo ◽  
Hiroyuki Toda ◽  
Masakazu Kobayashi ◽  
Kentaro Uesugi ◽  
Akihisa Takeuchi ◽  
...  

Author(s):  
R-R. Lee

Partially-stabilized ZrO2 (PSZ) ceramics have considerable potential for advanced structural applications because of their high strength and toughness. These properties derive from small tetragonal ZrO2 (t-ZrO2) precipitates in a cubic (c) ZrO2 matrix, which transform martensitically to monoclinic (m) symmetry under applied stresses. The kinetics of the martensitic transformation is believed to be nucleation controlled and the nucleation is always stress induced. In situ observation of the martensitic transformation using transmission electron microscopy provides considerable information about the nucleation and growth aspects of the transformation.


1993 ◽  
Vol 308 ◽  
Author(s):  
Paul R. Besser ◽  
Thomas N. Marieb ◽  
John C. Bravman

ABSTRACTStrain relaxation in passivated Al-0.5% Cu lines was measured using X-ray diffraction coupled with in-situ observation of the formation and growth of stress induced voids. Samples of 1 μm thick Al-0.5% Cu lines passivated with Si3N4 were heated to 380ºC, then cooled and held at 150ºC. During the test, principal strains along the length, width, and height of the line were determined using a grazing incidence x-ray geometry. From these measurements the hydrostatic strain in the metal was calculated and strain relaxation was observed. The thermal cycle was duplicated in a high voltage scanning transmission electron microscope equipped with a backscattered electron detector. The 1.25 μm wide lines were seen to have initial stress voids. Upon heating these voids reduced in size until no longer observable. Once the samples were cooled to 150ºC, voids reappeared and grew. The measured strain relaxation is discussed in terms of void and θ-phase (Al2Cu) formation.


ChemInform ◽  
2006 ◽  
Vol 37 (12) ◽  
Author(s):  
Katsuhiro Kobayashi ◽  
Tadashi Hata ◽  
Hiroshi Fukuhara ◽  
Yuji Ohashi
Keyword(s):  

2011 ◽  
Vol 59 (5) ◽  
pp. 1995-2008 ◽  
Author(s):  
H. Toda ◽  
E. Maire ◽  
S. Yamauchi ◽  
H. Tsuruta ◽  
T. Hiramatsu ◽  
...  

2008 ◽  
Vol 1142 ◽  
Author(s):  
Hideto Yoshida ◽  
Seiji Takeda ◽  
Tetsuya Uchiyama ◽  
Hideo Kohno ◽  
Yoshikazu Homma

ABSTRACTNucleation and growth processes of carbon nanotubes (CNTs) in iron catalyzed chemical vapor deposition (CVD) have been observed by means of in-situ environmental transmission electron microscopy. Our atomic scale observations demonstrate that solid state iron carbide (Fe3C) nanoparticles act as catalyst for the CVD growth of CNTs. Iron carbide nanoparticles are structurally fluctuated in CVD condition. Growth of CNTs can be simply explained by bulk diffusion of carbon atoms since nanoparticles are carbide.


2018 ◽  
Vol 25 (6) ◽  
pp. 1673-1682 ◽  
Author(s):  
Adam S. Hoffman ◽  
Joseph A. Singh ◽  
Stacey F. Bent ◽  
Simon R. Bare

In situ characterization of catalysts gives direct insight into the working state of the material. Here, the design and performance characteristics of a universal in situ synchrotron-compatible X-ray diffraction cell capable of operation at high temperature and high pressure, 1373 K, and 35 bar, respectively, are reported. Its performance is demonstrated by characterizing a cobalt-based catalyst used in a prototypical high-pressure catalytic reaction, the Fischer–Tropsch synthesis, using X-ray diffraction. Cobalt nanoparticles supported on silica were studied in situ during Fischer–Tropsch catalysis using syngas, H2 and CO, at 723 K and 20 bar. Post reaction, the Co nanoparticles were carburized at elevated pressure, demonstrating an increased rate of carburization compared with atmospheric studies.


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