scholarly journals Exposure of mass-selected bimetallic Pt–Ti nanoalloys to oxygen explored using scanning transmission electron microscopy and density functional theory

RSC Advances ◽  
2018 ◽  
Vol 8 (48) ◽  
pp. 27276-27282 ◽  
Author(s):  
Saeed Gholhaki ◽  
Shih-Hsuan Hung ◽  
David J. H. Cant ◽  
Caroline E. Blackmore ◽  
Alex G. Shard ◽  
...  

Theoretical and experimental morphology induced by oxidation of the Ti element.

2011 ◽  
Vol 17 (S2) ◽  
pp. 1316-1317 ◽  
Author(s):  
S Pantelides ◽  
T Pennycook ◽  
W Luo ◽  
M Prange ◽  
H Lee ◽  
...  

Extended abstract of a paper presented at Microscopy and Microanalysis 2011 in Nashville, Tennessee, USA, August 7–August 11, 2011.


2015 ◽  
Vol 21 (4) ◽  
pp. 946-952 ◽  
Author(s):  
J. Houston Dycus ◽  
Joshua S. Harris ◽  
Xiahan Sang ◽  
Chris M. Fancher ◽  
Scott D. Findlay ◽  
...  

AbstractHere, we report reproducible and accurate measurement of crystallographic parameters using scanning transmission electron microscopy. This is made possible by removing drift and residual scan distortion. We demonstrate real-space lattice parameter measurements with <0.1% error for complex-layered chalcogenides Bi2Te3, Bi2Se3, and a Bi2Te2.7Se0.3 nanostructured alloy. Pairing the technique with atomic resolution spectroscopy, we connect local structure with chemistry and bonding. Combining these results with density functional theory, we show that the incorporation of Se into Bi2Te3 causes charge redistribution that anomalously increases the van der Waals gap between building blocks of the layered structure. The results show that atomic resolution imaging with electrons can accurately and robustly quantify crystallography at the nanoscale.


Author(s):  
F. Khoury ◽  
L. H. Bolz

The lateral growth habits and non-planar conformations of polyethylene crystals grown from dilute solutions (<0.1% wt./vol.) are known to vary depending on the crystallization temperature.1-3 With the notable exception of a study by Keith2, most previous studies have been limited to crystals grown at <95°C. The trend in the change of the lateral growth habit of the crystals with increasing crystallization temperature (other factors remaining equal, i.e. polymer mol. wt. and concentration, solvent) is illustrated in Fig.l. The lateral growth faces in the lozenge shaped type of crystal (Fig.la) which is formed at lower temperatures are {110}. Crystals formed at higher temperatures exhibit 'truncated' profiles (Figs. lb,c) and are bound laterally by (110) and (200} growth faces. In addition, the shape of the latter crystals is all the more truncated (Fig.lc), and hence all the more elongated parallel to the b-axis, the higher the crystallization temperature.


2000 ◽  
Vol 638 ◽  
Author(s):  
Alan D.F. Dunbar ◽  
Matthew P. Halsall ◽  
Uschi Bangert ◽  
Alan Harvey ◽  
Philip Dawson ◽  
...  

AbstractWe report optical and scanning transmission electron microscopy studies of germanium dots grown on silicon. In an attempt to control the self-organized growth process and promote dot size uniformity the dot layers were grown on a 4.5nm Si0.6Ge0.4 alloy template layer. Photoluminescence results indicate the formation of carrier confining Ge rich islands, whilst Raman scattering results indicate the presence of an alloy throughout the structures formed. The samples were studied in the UK high resolution scanning transmission electron microscopy facility at Liverpool, UK. Energy dispersive analysis of individual line scans through the sample show that the structures are composed of an alloy throughout with an asymmetric distribution of Germanium in the dots and in the wetting layer close to the dots. We discuss the results in the light of the proposed growth mode for these dots and conclude that attempts to manipulate the composition of these dots during growth may be problematic due to the self-organized nature of their formation.


2010 ◽  
Vol 16 (S2) ◽  
pp. 1116-1117
Author(s):  
PJ Kempen ◽  
AS Thakor ◽  
CL Zavaleta ◽  
SS Gambhir ◽  
R Sinclair

Extended abstract of a paper presented at Microscopy and Microanalysis 2010 in Portland, Oregon, USA, August 1 – August 5, 2010.


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