Structure Analysis of Ni-Silicides Formed in Lateral Diffusion Couples

1984 ◽  
Vol 37 ◽  
Author(s):  
S. H. Chen ◽  
J. C. Barbour ◽  
L. R. Zheng ◽  
C. B. Carter ◽  
J. W. Mayer
Keyword(s):  
Electron Microscopy ◽  
Phase Diagram ◽  
High Resolution ◽  
Structure Analysis ◽  
Composition Range ◽  
Lateral Diffusion ◽  
High Resolution Electron Microscopy ◽  
The Other ◽  
Diffusion Couples ◽  
Resolution Electron

AbstractThe microstructures of the silicide Ni5Si2, which formed in self-supporting Ni-Si lateral-diffusion couples has been studied using high-resolution electron microscopy. Two different polymorphs (or polytypes) for Ni5Si2 have been observed. The actual composition of one polytype is confirmed to be Ni31Si12, while the other one has not yet been identified. Variations in the distribution of the two polytypes, as observed in the present study, may account for the composition range of Ni5Si2 in the Ni-Si phase diagram.

High-resolution electron microscopy studies of Ni silicides formed in lateral diffusion couples

1985 ◽  
Vol 18 (1-4) ◽  
pp. 297-303 ◽  
Author(s):  
S.H. Chen ◽  
Z. Elgat ◽  
J.C. Barbour ◽  
L.R. Zheng ◽  
J.W. Mayer ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Lateral Diffusion ◽  
High Resolution Electron Microscopy ◽  
Diffusion Couples ◽  
Resolution Electron ◽  
Ni Silicides

Direct structure analysis of advanced nanomaterials by high-resolution electron microscopy

2012 ◽  
Vol 1 (5) ◽  
pp. 389-425 ◽  
Author(s):  
Takeo Oku
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Nanostructured Materials ◽  
Structure Analysis ◽  
Incident Beam ◽  
High Resolution Electron Microscopy ◽  
Structure Model ◽  
Resolution Electron ◽  
Correction Technique ◽  
Resolution Imaging

AbstractHigh-resolution electron microscopy (HREM) analysis has contributed to the direct structure analysis of advanced nanostructured materials, of which the properties of these materials are strongly dependent on the atomic arrangements. In the present article, the direct structure analysis of nanostructured materials such as boride and oxide materials was described and the high-resolution imaging methods were applied to boron nitride nanomaterials such as nanotubes and nanoparticles. An aberration correction technique is also expected as an advanced nanostructure analysis with higher resolution. The HREM image of TlBa2Ca3Cu4O11 was taken with the incident beam parallel to the a axis together with a structure model after image processing.

Structure analysis of amorphous Pd75Si25 alloy by electron diffraction and high-resolution electron microscopy

1996 ◽  
Vol 217-218 ◽  
pp. 392-396 ◽  
Author(s):  
Mitsuhide Matsushita ◽  
Yoshibiko Hirotsu ◽  
Tadakatsu Ohkubo ◽  
Tetsuo Oikawa ◽  
Akihiro Makino
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Electron Diffraction ◽  
Structure Analysis ◽  
High Resolution Electron Microscopy ◽  
Resolution Electron

High-Resolution Electron Microscopy of condensed clusters in a potassium barium oxomolybdate

1994 ◽  
Vol 52 ◽  
pp. 648-649
Author(s):  
R. Ramlau ◽  
G. L. Schimek ◽  
R. E. McCarley ◽  
A. Simon
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Structure Analysis ◽  
High Resolution Electron Microscopy ◽  
General Concept ◽  
Molybdenum Oxides ◽  
Compound K ◽  
Space Group ◽  
X Ray ◽  
Resolution Electron

The recently synthesized compound K0.19Ba3.81Mo22O34 is a representative of the ternary and quaternary reduced molybdenum oxides in which clusters built from molybdenum octahedra are arranged in layers of composition AxByMo4n+2O6n+4. The number of trans-edgesharing molybdenum octahedra in the cluster is represented by n. The general concept of cluster condensation is formulated and discussed elsewhere. For K0.19Ba3.81Mo22O34, n is equal to 5. A ternary representative, likewise with n = 5, is In6Mo22O34.By x-ray structure analysis, K0.19Ba3.81Mo22O34 proved to crystallize in space group P21/a with parameters a = 0.9908(2) nm, b = 0.9353(2) nm, c = 1.5951(3) nm, and β = 98.78(2)°. The potassium atoms were found to reside on the same sites as the barium atoms with an almost statistical distribution.We studied K0.19Ba3.81Mo22O34 by high-resolution electron microscopy (HREM). Small fragments of a crystal were investigated using a Philips CM30/ST microscope operating at 300 kV (point resolution 0.19 nm). At appropriate orientations of the crystal fragments, HREM images reveal domains of two ordered polytypes: a monoclinic and an orthorhombic one (Figs. 1 and 2).

Electron Microscopy characterisation of fluorinated zeolites

1990 ◽  
Vol 48 (4) ◽  
pp. 276-277
Author(s):  
V. Castaño ◽  
A. Vázquez ◽  
J. Saniger ◽  
N. Sánchez ◽  
J. Flores
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
High Resolution Electron Microscopy ◽  
The Other ◽  
Resolution Image ◽  
Edx Analysis ◽  
High Resolution Image ◽  
Zeolite Structure ◽  
Resolution Electron ◽  
Acidic Sites

Zeolites constitute one of today 's most important materials in Catalysis and their characterisation, in every respect, remains a challenge for scientists in the field. Generally speaking, zeolites can be classified as follows: a) High Si/Al ratio zeolites and b) Zeolites with a small Si/Al relationship. Obviously, many of the properties are quite different for the two types of zeolites since low Si/Al zeolites have less acidic sites of high catalytic strength. Thus, it is important to devise a simple and efficient way to modify low Si/Al zeolites to have higher Si to A1 ratios. One way for achieveing this is via the modification with F of 4A-type zeolites. Figures 1 and 2 show a comparative EDX analysis of an unchanged zeolite and of a fluorinated one, respectively. As can be observed there, the Si/Al ratio remains basically the same, result that is contrary to some previous reports which claimed a loss of A1 during the fluorination. High Resolution Electron Microscopy, on the other hand, shows interesting changes at the microstructural level since some amorphization of the fluorinated samples was detected, as can be observed in the digitally processed high resolution image of figure 3. From our electron microscopy studies we conclude that, for low-pressure fluorination conditions, the zeolites behaves as an inert support for the F whereas for higher pressures the F is incorporated to the zeolite structure

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