Oxygen Interaction with Hexagonal OsB2 at High Temperature |
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| Authors: | Zhilin Xie Richard G. Blair Nina Orlovskaya David A. Cullen Dariusz Kata Paweł Rutkowski Jerzy Lis Nan Qin Ali T‐Raissi |
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| Affiliation: | 1. Department of Mechanical and Aerospace Engineering, University of Central Florida, Orlando, Florida;2. Department of Physics, University of Central Florida, Orlando, Florida;3. Materials Science & Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee;4. Faculty of Materials Science and Ceramics, Department of Ceramics and Refractories, AGH University of Science and Technology in Krakow, Krakow, Poland;5. Florida Solar Energy Center, University of Central Florida, Cocoa, Florida |
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| Abstract: | The stability of ReB2‐type hexagonal OsB2 powder at high temperature with oxygen presence has been studied by thermogravimetric analysis, differential scanning calorimetry, SEM, EDS, and high‐temperature scanning transmission electron microscopy and XRD. Results of the study revealed that OsB2 ceramics interact readily with oxygen present in reducing atmosphere, especially at high temperature and produces boric acid, which decomposes on the surface of the powder resulting in the formation of boron vacancies in the hexagonal OsB2 lattice as well as changes in the stoichiometry of the compound. It was also found that under low oxygen partial pressure, sintering of OsB2 powders occurred at a relatively low temperature (900°C). Hexagonal OsB2 ceramic is prone to oxidation and it is very sensitive to oxygen partial pressures, especially at high temperatures. |
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| Keywords: | osmium diboride ceramics
STEM
thermal analysis |
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