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Vol.5 , No. 1, Publication Date: Apr. 25, 2019, Page: 1-7
 has been optimized to fabricate sintered CeO<sub>2</sub> microspheres. Optimisation of sol formulations was studied using cerium ammonium nitrate, HMTA and urea in the fabrication of cerium oxide microsphere. CeO<sub>2</sub> spheres doped with carbon powder have also been produced using this method and the reactive sintering parameters of CeN microsphere production have been optimized. Samples were placed in a crucible and heated to in a hydrogen-nitrogen atmosphere to control stoichiometry. Results showed cerium carbide with no oxide phase was detected using X ray diffraction (XRD). Results indicated that internal gelation successfully formed spheres of cerium oxide and carbon. The precipitation of Ce<sup>4+</sup> was corresponded to the pH of the solution and the formed gels. The pH-value determines the point of precipitation of Ce<sup>4+</sup>, and dictated the gelation time. Gelation time was observed through the colour change of the spheres from a translucent yellow to opaque white.&picture=http://www.aascit.org/aascit/decorators/img/journal/974.jpg)
| [1] | Osama Farid, Reactor Department, Atomic Energy Authority, Cairo, Egypt. |
| [2] | Farid H. Abou El-Nour, Nuclear Chemistry Department, Atomic Energy Authority, Cairo, Egypt. |
Non-oxide ceramics such as carbides and nitrides are potential fuel candidates to be used in Generation IV nuclear reactors. A fissile phase such as UN or PuN is dispersed with an inert phase such as ZrN and TiN to provide structure and retain fission products. In this study cerium was used as a surrogate element instead of U or Pu. Cerium nitride was fabricated by the carbothermic reduction of cerium oxide, This method was investigated and optimized. The internal gelation method (IGM) has been optimized to fabricate sintered CeO2 microspheres. Optimisation of sol formulations was studied using cerium ammonium nitrate, HMTA and urea in the fabrication of cerium oxide microsphere. CeO2 spheres doped with carbon powder have also been produced using this method and the reactive sintering parameters of CeN microsphere production have been optimized. Samples were placed in a crucible and heated to in a hydrogen-nitrogen atmosphere to control stoichiometry. Results showed cerium carbide with no oxide phase was detected using X ray diffraction (XRD). Results indicated that internal gelation successfully formed spheres of cerium oxide and carbon. The precipitation of Ce4+ was corresponded to the pH of the solution and the formed gels. The pH-value determines the point of precipitation of Ce4+, and dictated the gelation time. Gelation time was observed through the colour change of the spheres from a translucent yellow to opaque white.
Keywords
Non-Oxide Ceramic, Cerium Nitride Fabrication, CeO2 Spheres
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