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Properties and Applications of Rare Earth Oxides, Alloys, and Compounds
Published in A. R. Jha, Deployment of Rare Earth Materials in Microware Devices, RF Transmitters, and Laser Systems, 2019
The author wishes to summarize the potential applications of rare earth samarium metal. This particular rare earth metal was first discovered in 1879. It is also available as an oxide. However, the metallic version comes in various forms such as rods, wires, pellets, or sputtering targets. Thin films are best suited for precision optical coatings and high-performance capacitance for possible application in microwave circuits. As stated earlier, samarium is widely used in the design and development of high-performance permanent magnets, which are currently deployed for electric motors and generators. These motors and generators offer considerable reduction in weight and size, which is of critical importance for the auto industry. This rare earth metal in conjunction with cobalt forms a high-performance permanent magnet which can retain all its magnetic properties even at operating temperatures as high as 300°C. It is of paramount importance to mention that samarium–cobalt permanent magnets have been tested for improved reliability and magnetic performance in radar transmitters and dual-mode TWTAs deployed in airborne ECM jamming systems, where operating temperatures can rapidly approach 300°C under “after-burner” conditions. In summary, it can be stated that samarium–cobalt permanent magnets are best suited for applications where minimum weight and size, high reliability, and elevated operating temperatures are the principal design requirements.
Sintering and microstructural behaviors of mechanically blended Nd/Sm-doped MOX
Published in Journal of Nuclear Science and Technology, 2023
Shun Hirooka, Yuta Horii, Takeo Sunaoshi, Hiroki Uno, Tadahisa Yamada, Romain Vauchy, Kohei Hayashizaki, Shinya Nakamichi, Tatsutoshi Murakami, Masato Kato
Although no data on the fabrication of low decontaminated MOX (uranium-plutonium mixed oxide) fuels are available in the open literature, part of the FPs remaining in the fuel are expected to vaporize during denitration, calcination, and reduction processes. The nitrate solution is heated up to ~ 773 K during U-Pu denitration process, for example, by microwave heating, and the oxides precipitate above 573 K [4,5]. To obtain dioxides, the precipitates are calcined in air and reduced in an Ar-H2 gas mixture at 973 K. Powder XRD reveals that two phases, namely UO2 and PuO2, are formed by this process due to the differential precipitation of these species within the initial solution [6,7]. During heat treatment, volatile FPs, e.g. cesium (Cs) compounds, are released and hardly remain in the final dioxides even though they are the major inventories. However, lanthanide elements like neodymium (Nd) and samarium (Sm) are stable in their oxide forms throughout the process, and a significant amount of them is anticipated to remain in the fuel.
Finely Divided Metal as Nuclear Reactor Fuel
Published in Nuclear Technology, 2022
Europium is only 9.4% of fission products remaining in the electrolyte, but it contributes 90% of radiotoxicity (624.1 kSv) and produces 93% of thermal power (73.35 W). Its presence requires custody of the mineral waste form from electrolyte cleansing for about 100 years (see Fig. 4). Without it, custody would be less than 30 years. It could be removed as sulfate because its sulfate is the least soluble of the remaining elements by a factor of , assuming barium and strontium have been removed. Simply adding water to start a sulfate process to remove europium would remove silver and tin because AgCl is insoluble and tin chlorides hydrolyze to insoluble hydroxides. After silver, tin, and europium are removed, samarium constitutes 54% of remaining fission products and contributes 2.9% of remaining radiotoxicity. It could be removed by further titration using sulfate. After silver, tin, europium, and samarium are removed, only nonradioactive yttrium (95.4%), indium (0.41%), germanium (0.13%), and microgram quantities of others remain, along with antimony (4.1%). Reagent-grade YCl3 has a value of about $5000 per tonne of 5.2%-burnup fuel. The 125Sb half-life is 2.759 years and thermal power is 5.2 W. Their trichlorides can be separated by distillation or crystallization.
Characterization of the chemical shift and asymmetry indices of praseodium, neodymium, samarium, gadolinium, and terbium compounds by wavelength dispersive X-ray fluorescence (WDXRF)
Published in Instrumentation Science & Technology, 2023
Sevil (Porikli) Durdağı, Fatma Güzel
Table 2 shows that the orthorhombic Nd2(CO3)3.xH2O and Nd2(C2O4)3.xH2O are more symmetrical compared to the hexagonal NdCl3 and Nd2O3 compounds. All samarium compounds examined are in the +3 oxidation state with have a coordination number of 9 and are symmetrical structure for the cubic Sm2O3 compound. The crystal structure of SmF3 is orthorhombic and SmCl3 has a hexagonal structure. GdF3 and Gd2(SO4)3⋅8H2O X-ray emission lines with high coordination numbers suggest an asymmetrical structure.