ChemInform Abstract: MICROSTRUCTURE OF YTTRIUM OXIDE FLUXED HOT-PRESSED SILICON NITRIDE

1978 ◽  
Vol 9 (27) ◽  
Author(s):  
D. R. CLARKE ◽  
G. THOMAS
2001 ◽  
Vol 201 (2) ◽  
pp. 238-249 ◽  
Author(s):  
Y. S. Zheng ◽  
K. M. Knowles ◽  
J. M. Vieira ◽  
A. B. Lopes ◽  
F. J. Oliveira

2019 ◽  
Vol 107 (2) ◽  
pp. 179-191 ◽  
Author(s):  
Mustafa R. Kacal ◽  
Ferdi Akman ◽  
M. I. Sayyed

Abstract In this work, the radiation shielding parameters like mass and linear attenuation coefficient, half value layer, tenth value layer, mean free path, effective atomic number, effective electron density, exposure buildup factor and fast neutron removal cross section were examined for the peridot, aluminum nitride, ruby, yttrium oxide, magnesium silicate, and silicon nitride ceramic samples. Furthermore, the dependence of the effective conductivity on the energy was investigated. The experimental studies were carried out in the photon energy range of 81 keV–1333 keV using a high resolution HPGe detector and six different radioactive sources. The experimental results were validated with the theoretical results and a good agreement was observed for all samples. The yttrium oxide has more shielding effectiveness for γ radiation, while magnesium silicate, aluminum nitride and silicon nitride possess least γ-ray shielding. However, the optimum neutron shielding material is ruby.


1996 ◽  
Vol 432 ◽  
Author(s):  
Michael Buchta ◽  
Wei-Heng Shih

AbstractTo improve the processing of silicon nitride, boehmite and yttrium oxide were coated on silicon nitride particles by an aqueous sol-gel method. It is shown that boehmite and Y2O3 can be coated on Si3N4 particles from aqueous solutions. However, the Y2O3 coating is not as complete as boehmite coating. The coating of a yttria coating followed by a boehmite coating was attempted and the TEM showed a coating twice as thick as the Y2O3 or AlOOH coating. Hydrothermal treatment of yttrium nitrate hydrous hydroxide results in the formation and growth of Y(OH)3 fibers which can be calcined and transformed into Y2O3 fibers at 500°C.


1980 ◽  
Vol 11 (21) ◽  
Author(s):  
L. J. GAUCKLER ◽  
H. HOHNKE ◽  
T. Y. TIEN

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