Analytical Electron Microscopy of Solid Catalysts

1982 ◽  
Vol 40 ◽  
pp. 660-663
Author(s):  
F. Delannay
Keyword(s):  
Electron Microscopy ◽  
Analytical Electron Microscopy ◽  
Supported Metal Catalysts ◽  
X Ray ◽  
Solid Catalysts ◽  
Transmission Electron ◽  
Analytical Electron ◽  
Conventional Transmission Electron Microscope ◽  
Electron Microdiffraction

Practical catalysts are usually intricate mixtures of phases which cannot be characterized separately unless looked at below the micron scale. For about two decades, electron microscopy has been a priviledged complement to selective chemisorption methods for the study of supported metal catalysts. Until recently, however, reliable tools allowing characterization of oxide and sulfide catalysts (e.g. for selective oxidation and hydrodesulfurization reactions) have been lacking. This contribution aims at illustrating the new insights into the understanding of these systems which have been provided by the combination of thin film X-ray microanalysis and electron microdiffraction within a conventional transmission electron microscope with STEM and EDS attachments.

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.

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).

Characterization of Si(Li) x-ray detector efficiencies in the low energy range

1986 ◽  
Vol 44 ◽  
pp. 710-711
Author(s):  
G. Wirmark ◽  
G. Wahlberg ◽  
H. Nordén
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Energy Range ◽  
Analytical Electron Microscopy ◽  
Low Energy ◽  
Ratio Method ◽  
X Ray ◽  
Standard Specimens ◽  
Analytical Electron

X-ray microanalysis with windowless or ultra-thin window Si(Li)-detectors is becoming increasingly important in analytical electron microscopy. The most common approach in the quantification of this method is the thin film ratio method.where CA and CB denote the concentrations of elements A and B respectively and IA and IB are the corresponding x-ray intensities. The KAB-factor should ideally be determined from analyses of standard specimens of known compositions.

scholarly journals Correlative 3D-Characterization of Liquid Metal Catalysts (LMC) utilizing X-ray and Analytical Electron Microscopy

2018 ◽  
Vol 24 (S2) ◽  
pp. 556-557 ◽  
Author(s):  
Janis Wirth ◽  
Silvan Englisch ◽  
Christian Wiktor ◽  
Nicola Taccardi ◽  
Peter Wasserscheid ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Liquid Metal ◽  
Analytical Electron Microscopy ◽  
Metal Catalysts ◽  
X Ray ◽  
Analytical Electron

Characterization of Nanocomposite Coatings in the System Ti-B-N by Analytical Electron Microscopy and X-Ray Photoelectron Spectroscopy

2002 ◽  
pp. 101-112 ◽  
Author(s):  
Andreas Gupper ◽  
Asunción Fernández ◽  
Christina Fernández-Ramos ◽  
Ferdinand Hofer ◽  
Christian Mitterer ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Analytical Electron Microscopy ◽  
Nanocomposite Coatings ◽  
X Ray ◽  
Analytical Electron

Origin of mixed-layered (R1) muscovite-chlorite in an anchizonal slate from Puncoviscana Formation (Salta Province, Argentina)

Clay Minerals ◽  
2005 ◽  
Vol 40 (3) ◽  
pp. 317-332 ◽  
Author(s):  
M. Do Campo ◽  
F. Nieto
Keyword(s):  
Electron Microscopy ◽  
Mixed Layer ◽  
Analytical Electron Microscopy ◽  
Aqueous Fluid ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Analytical Electron ◽  
Dioctahedral Mica ◽  
Mixed Layering

AbstractMica-chlorite mixed-layering was identified by X-ray diffraction (XRD) as a major or subordinate constituent in several slates of the Puncoviscana Formation from Sierra de Mojotoro (Eastern Cordillera, NW Argentina). In order to determine the crystallochemical characteristics of these mixed-layered sequences and interpret their petrological meaning, anchizonal slate P90 was chosen for TEM observations. In this slate, dioctahedral mica and chlorite form interleaved phyllosilicate grains (IPG) or stacks, up to 110 um long, preferentially oriented with (001) planes at a high angle to the slaty cleavage but also oblique to S0.In agreement with XRD results, the main phyllosilicates identified by transmission electron microscopy (TEM) were dioctahedral mica and random mixed-layer muscovite-chlorite, with chlorite in subordinate amounts and scarce smectite. In the lattice-fringe images of mixed-layer packets, a sequence of irregular stacking that produced apparent 24 Å (10 + 14) layers was observed, but it was frequently possible to distinguish the 10 Å layers from adjacent 14 Å layers. In nearly all packets, 14 Å layers prevail, exhibiting 14 Å:10 Å ratios between 1:1 and 3:1. Some elongated lenticular fissures which are probably a consequence of layer collapse caused by the TEM vacuum were identified in these packets. The straight, continuous appearance of lattice fringes plus the scarce evidence of collapsed layers identified suggest that these packets correspond principally to mixed-layer muscovite-chlorite, which is confirmed by analytical electron microscopy analyses. However, smectite-like layers are probably the third component of some of these mixed-layer sequences, which may account for their high Si and low (Fe + Mg) contents, their low interlayer charge in relation to theoretical interlayer muscovite-chlorite, and for the presence of Ca in the interlayer site.Textural relationships between chlorite and muscovite packets in IPG along with the observed transformations from 14 Å to 10 Å along the layer, is compatible with a prograde metamorphic replacement of chlorite in stacks by dioctahedral mica layers, probably in the presence of an aqueous fluid.

AEM Study of thin and Thick Film Metallization on AIN Substrates

1987 ◽  
Vol 108 ◽  
Author(s):  
Alistair D. Westwood ◽  
Michael R. Notis
Keyword(s):  
Electron Microscopy ◽  
Thick Film ◽  
Analytical Electron Microscopy ◽  
Microstructural Characterization ◽  
Convergent Beam Electron Diffraction ◽  
Transmission Electron ◽  
Analytical Electron ◽  
Convergent Beam ◽  
Boundary Penetration

ABSTRACTMicrostructural characterization of thin film (Au-Pt-Ti) and thick film (Mo-Mn) metallization on AIN substrates has been performed using Transmission Electron Microscopy (TEM), Analytical Electron Microscopy (AEM), Convergent Beam Electron Diffraction (CBED) and Auger Electron Spectroscopy (AES). The reaction mechanisms for both types of metallization methods are proposed. In particular, the microchemical and morphological nature of grain boundary penetration and precipitation within the AIN near the metallization interface has been examined.

Sign in / Sign up

Export Citation Format

Share Document