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Structure and properties of uranium oxide thin films deposited by pulsed dc magnetron sputtering
| Content Provider | Semantic Scholar |
|---|---|
| Author | Lin, Jianliang Dahan, Isaac J. Valderrama, Billy Manuel, Michele V. |
| Copyright Year | 2014 |
| Abstract | a b s t r a c t Crystalline uranium oxide thin films were deposited in an unbalanced magnetron sputtering system by sputtering from a depleted uranium target in an Ar + O2 mixture using middle frequency pulsed dc magnetron sputtering. The substrate temperature was constantly maintained at 500 ◦C. Different uranium oxide phases (including UO2−x, UO2, U3O7 and U3O8) were obtained by controlling the percentage of the O2 flow rate to the total gas flow rate (fO2 ) in the chamber. The crystal structure of the films was characterized using X-ray diffraction and the microstructure of the films was studied using transmission electron microscopy and atom probe tomography. When the fO2 was below 10%, the film contains a mixture of metallic uranium and UO2−x phases. As the fO2 was controlled in the range of 10-13%, UO2 films with a (2 2 0) preferential orientation were obtained. The oxide phase rapidly changed to a mixture of U3O7 and U3O8 as the fO2 was increased to the range of 15-18%. Further increasing the fO2 to 20% and above, polycrystalline U3O8 thin films with a (0 0 1) preferential orientation were formed. The hardness and Young's modulus of the uranium oxide films were evaluated using nanoindentation. The film containing a single UO2 phase exhibited the maximum hardness of 14.3 GPa and a Young's modulus of 195 GPa. The UO2 thin film also exhibited good thermal stability in that no phase change was observed after annealing at 600 ◦ C in vacuum for 104 h. |
| Starting Page | 475 |
| Ending Page | 480 |
| Page Count | 6 |
| File Format | PDF HTM / HTML |
| DOI | 10.1016/j.apsusc.2014.02.106 |
| Alternate Webpage(s) | https://nsuf.inl.gov/Publication/DownloadDocument/29 |
| Alternate Webpage(s) | https://doi.org/10.1016/j.apsusc.2014.02.106 |
| Volume Number | 301 |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
