Irradiated rare-earth-doped powellite single crystal probed by confocal Raman mapping and transmission electron microscopy

2014 ◽  
Vol 45 (5) ◽  
pp. 383-391 ◽  
Author(s):  
X. Wang ◽  
G. Panczer ◽  
D. de Ligny ◽  
V. Motto-Ros ◽  
J. Yu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Rare Earth ◽  
Single Crystal ◽  
Raman Mapping ◽  
Transmission Electron ◽  
Confocal Raman ◽  
Rare Earth Doped

Nonepitaxial heterogeneous nucleation of α-sialon in the Ca-doped system

2001 ◽  
Vol 16 (2) ◽  
pp. 578-582 ◽  
Author(s):  
Ya-Wen Li ◽  
Pei-Ling Wang ◽  
Wei-Wu Chen ◽  
Jing-Wei Feng ◽  
Yi-Bing Cheng ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Rare Earth ◽  
Orientation Relationship ◽  
Heterogeneous Nucleation ◽  
Crystallographic Orientation ◽  
Probable Mechanism ◽  
Transmission Electron ◽  
Low X ◽  
Rare Earth Doped

Ca-α-sialon compacts pressureless-sintered to intermediate temperatures, which consisted of both α-sialon and unreacted α–Si3N4 grains, were investigated with transmission electron microscopy for an overall composition Ca1.8Si6.6Al5.4O1.8N14.2. Special attention was paid to identification of the possible crystallographic orientation between a-sialon and the α–Si3N4 particles. In contrast to the frequently occurring heteroepitaxial nucleation of α-sialon in rare-earth-doped samples with low x values, this study showed that most of the newly formed α-sialon grains had no epitaxial orientation relationship with the α–Si3N4 particles, suggesting nonepitaxial heterogeneous nucleation to be a more probable mechanism for the Ca–α-sialon phase with high Ca concentrations.

Determination of Dislocation Densities in Hexagonal Close-Packed Metals using X-Ray Diffraction and Transmission Electron Microscopy

1991 ◽  
Vol 35 (A) ◽  
pp. 593-599 ◽  
Author(s):  
M. Griffiths ◽  
J.E. Winegar ◽  
J.F. Mecke ◽  
R.A. Holt
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Single Crystal ◽  
Plastic Anisotropy ◽  
Zirconium Alloys ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hexagonal Close Packed ◽  
Transmission Electron ◽  
Dislocation Densities

AbstractX-ray diffraction (XRD) line-broadening analysis has been used to determine dislocation densities in zirconium alloys with hexagonal closepacked (hep) crystal structures and a complex distribution of dislocations reflecting the plastic, anisotropy of the material. The validity of the technique has been assessed by comparison with direct measurements of dislocation densities in deformed polycrystalline and neutron-irradiated single crystal material using transmission electron microscopy (TEM). The results show that-there is good agreement between the XRD and TEM for measurements on the deformed material whereas there is a large discrepancy for measurements on the irradiated single crystal; the XRD measurements significantly underestimating the TEM observations.

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