High Spatial Resolution Assessment of the Structure, Composition, and Electronic Properties of Nanowire Arrays

2001 ◽  
Vol 635 ◽  
Author(s):  
M.S. Sander ◽  
A.L. Prieto ◽  
Y.M. Lin ◽  
R. Gronsky ◽  
A.M. Stacy ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Electronic Properties ◽  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Analytical Electron Microscopy ◽  
Nanowire Arrays ◽  
Composition Gradient ◽  
Transmission Electron ◽  
Analytical Electron ◽  
Electron Energy Loss

AbstractWe have employed transmission electron microscopy (TEM) and analytical electron microscopy to perform preliminary assessment of the structure, composition and electronic properties of nanowire arrays at high spatial resolution. The two systems studied were bismuth and bismuth telluride nanowire arrays in alumina (wire diameters ~40nm), both of which are promising for thermoelectric applications. Imaging coupled with diffraction in the TEM was employed to determine the grain size in electrodeposited Bi2Te3 nanowires. In addition, a composition gradient was identified along the wires in a short region near the electrode by energy-dispersive x-ray spectroscopy. Electron energy loss spectroscopy combined with energy-filtered imaging in the TEM revealed the excitation energy and spatial variation of plasmons in bismuth nanowire arrays.

High spatial resolution analytical electron microscopy studies on the Co/CeO2 system

1988 ◽  
Vol 12 (1) ◽  
pp. 3-10 ◽  
Author(s):  
C. Colliex ◽  
D. Ugarte ◽  
Z. L. Wang ◽  
M. Gasgnier ◽  
V. Paul-Boncour
Keyword(s):  
Electron Microscopy ◽  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Analytical Electron Microscopy ◽  
Analytical Electron

scholarly journals Ammonium-bearing micas in very low-grade metapelites: micro- and nano-texture and composition

Clay Minerals ◽  
2018 ◽  
Vol 53 (2) ◽  
pp. 105-116 ◽  
Author(s):  
Blanca Bauluz ◽  
Fernando Nieto
Keyword(s):  
Electron Microscopy ◽  
Analytical Electron Microscopy ◽  
Low Grade ◽  
X Ray Diffraction ◽  
Iberian Range ◽  
Transmission Electron ◽  
Analytical Electron ◽  
Ir Transmission ◽  
Electron Energy Loss ◽  
Two Populations

ABSTRACTThe present study examines the micro- and nano-texture and composition of ammonium-bearing and potassium micas in very-low grade metamorphic black Silurian shales from the SE Iberian Range (NE Spain). Two organic-rich shales were studied by X-ray diffraction (XRD), infrared spectroscopy (IR), transmission electron microscopy (TEM), analytical electron microscopy (AEM) and electron energy loss spectroscopy (EELS). The XRD showed the presence of two populations of micas: pure K micas with d001 = 9.98 Å and ammonium-bearing micas with larger d001 values (10.08 Å and 10.05 Å). The latter values indicate NH4 contents between 13 and 29% in the interlayer, which was confirmed by IR. Interstratifications of smectite and mica layers in the mica packets were not detected by XRD and TEM. Mica packets with sizes ranging from 100 to 250 Å show disordered polytypes and (001) lattice fringes that reflect the presence of K- and NH4-bearing layers (9.9–10.2 Å).The combination of AEM and EELS analyses on powdered and lamellar samples indicates that micas have typical dioctahedral compositions with highly variable K contents. This variation in K is consistent with the presence of K and NH4 in the interlayers, even though the NH4 and K are not distributed homogeneously; rather they are segregated in nm-sized domains in the mica interlayer.

Structure and Composition of Bismuth Nanowire Arrays

1999 ◽  
Vol 581 ◽  
Author(s):  
M. S. Sander ◽  
Y-M. Lin ◽  
M. S. Dresselhaus ◽  
R. Gronsky
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Porous Alumina ◽  
Analytical Electron Microscopy ◽  
Nanowire Arrays ◽  
Bismuth Nanowire ◽  
Liquid Bismuth ◽  
Transmission Electron ◽  
Analytical Electron ◽  
Recent Attention

ABSTRACTArrays of nanowires have attracted considerable recent attention due to their unique electronic and optical properties. While much effort has been directed at fabricating arrays and measuring their properties, much less has been done to characterize these materials. Understanding the structure and composition of the constituents in these arrays is crucial in order to control their properties. In this work, arrays with wire diameters from 35-90nm were fabricated by pressure injecting liquid bismuth into porous alumina templates. Transmission electron microscopy (TEM) and analytical electron microscopy (AEM) were used to characterize the arrays.

The effect of small additions of Cu on precipitation in Al-Mg-Si alloys

1990 ◽  
Vol 48 (2) ◽  
pp. 442-443
Author(s):  
M. Tamizifar ◽  
G. Cliff ◽  
R.W. Devenish ◽  
G.W. Lorimer
Keyword(s):  
Electron Microscopy ◽  
Analytical Electron Microscopy ◽  
Scanning Transmission Electron Microscope ◽  
Argon Atmosphere ◽  
Age Hardening ◽  
X Ray ◽  
Transmission Electron ◽  
Heat Treated ◽  
Analytical Electron ◽  
Scanning Transmission

Small additions of copper, <1 wt%, have a pronounced effect on the ageing response of Al-Mg-Si alloys. The object of the present investigation was to study the effect of additions of copper up to 0.5 wt% on the ageing response of a series of Al-Mg-Si alloys and to use high resolution analytical electron microscopy to determine the composition of the age hardening precipitates.The composition of the alloys investigated is given in Table 1. The alloys were heat treated in an argon atmosphere for 30m, water quenched and immediately aged either at 180°C for 15 h or given a duplex treatment of 180°C for 15 h followed by 350°C for 2 h2. The double-ageing treatment was similar to that carried out by Dumolt et al. Analyses of the precipitation were carried out with a HB 501 Scanning Transmission Electron Microscope. X-ray peak integrals were converted into weight fractions using the ratio technique of Cliff and Lorimer.

The Use of ELNES for Microanalysis

1999 ◽  
Vol 5 (S2) ◽  
pp. 664-665
Author(s):  
A.J. Craven ◽  
M. MacKenzie
Keyword(s):  
Electron Microscopy ◽  
Energy Loss ◽  
Electron Energy ◽  
Analytical Electron Microscopy ◽  
Local Environment ◽  
Edge Structure ◽  
Similar Shape ◽  
Analytical Electron ◽  
Electron Energy Loss ◽  
Combining Information

The performance of many materials systems depends on our ability to control the distribution of atoms on a nanometre or sub-nanometre scale within those systems. This is as true for steels as it is for semiconductors. A key requirement for improving their performance is the ability to determine the distribution of the elements resulting from processing the material under a given set of conditions. Analytical electron microscopy (AEM) provides a range of powerful techniques with which to investigate this distribution. By combining information from different techniques, many of the ambiguities of interpretation of the data from an individual technique can be eliminated. The electron energy loss near edge structure (ELNES) present on an ionisation edge in the electron energy loss spectrum reflects the local structural and chemical environments in which the particular atomic species occurs. Thus it is a useful contribution to the information available. Since a similar local environment frequently results in a similar shape, ELNES is useful as a “fingerprint”.

scholarly journals Analytical High-resolution Electron Microscopy Reveals Organ-specific Nanoceria Bioprocessing

2017 ◽  
Vol 46 (1) ◽  
pp. 47-61 ◽  
Author(s):  
Uschi M. Graham ◽  
Robert A. Yokel ◽  
Alan K. Dozier ◽  
Lawrence Drummy ◽  
Krishnamurthy Mahalingam ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Analytical Electron Microscopy ◽  
High Resolution Electron Microscopy ◽  
Dark Field ◽  
Transmission Electron ◽  
Analytical Electron ◽  
Organ Specific

This is the first utilization of advanced analytical electron microscopy methods, including high-resolution transmission electron microscopy, high-angle annular dark field scanning transmission electron microscopy, electron energy loss spectroscopy, and energy-dispersive X-ray spectroscopy mapping to characterize the organ-specific bioprocessing of a relatively inert nanomaterial (nanoceria). Liver and spleen samples from rats given a single intravenous infusion of nanoceria were obtained after prolonged (90 days) in vivo exposure. These advanced analytical electron microscopy methods were applied to elucidate the organ-specific cellular and subcellular fate of nanoceria after its uptake. Nanoceria is bioprocessed differently in the spleen than in the liver.

Mixed-layer mica-chlorite in very low-grade metaclastites from the Malàguide Complex (Betic Cordilleras, Spain)

Clay Minerals ◽  
2001 ◽  
Vol 36 (3) ◽  
pp. 307-324 ◽  
Author(s):  
M. D. Ruiz Cruz
Keyword(s):  
Electron Microscopy ◽  
Mixed Layer ◽  
Analytical Electron Microscopy ◽  
Low Grade ◽  
X Ray ◽  
Betic Cordilleras ◽  
Transmission Electron ◽  
Analytical Electron ◽  
Microscopy Data ◽  
Ray Patterns

AbstractMixed-layered phyllosilicates with composition intermediate between mica and chlorite were identified in very low-grade metaclastites from the Malàguide Complex (Betic Cordilleras, Spain), and studied by X-ray diffraction, and transmission and analytical electron microscopy. They occur both as small grains in the rock matrix, and associated with muscovitechlorite stacks. Transmission electron microscope observations revealed a transition from chlorite to ordered 1:1 interstratifications through complex 1:2 and 1:3 interstratifications. Analytical electron microscopy data indicate a composition slightly different from the sum of discrete trioctahedral chlorite and dioctahedral mica. The types of layer transitions suggest that mixed-layer formation included two main processes: (1) the replacement of a brucite sheet by a cation sheet in the chlorite structure; and (2) the precipitation of mica-like layers between the chlorite layers. The strongest diffraction lines in oriented X-ray patterns are: 12.60 Å (002), 7.98 Å (003), 4.82 Å (005) and 3.48 Å (007).

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