We obtained the reaction mechanism of cerium with oxygen by means of density functional theory (DFT) under the explosive or detonation situation. The energy level order of cerium was calculated and the potential energ...We obtained the reaction mechanism of cerium with oxygen by means of density functional theory (DFT) under the explosive or detonation situation. The energy level order of cerium was calculated and the potential energy profile was plotted. The properties of the bonds of all special structures in the reaction path were analyzed using the method of the electron localization function (ELF). The results indicate that the final reaction pathway can be expressed as Ce+O2→ FC→TS→IM→O-Ce-O, and the formation of Ce2O3 has not been found. In addition, the ELF diagram of the final product CeO2 shows that Ce bonds with both O atoms and the bond angles increase significantly.展开更多
He defect properties in Sc, Y, Gd, Tb, Dy, Ho, Er and Lu were studied using first-principles calculations based on density functional theory. The results indicate that the formation energy of an interstitial He atom i...He defect properties in Sc, Y, Gd, Tb, Dy, Ho, Er and Lu were studied using first-principles calculations based on density functional theory. The results indicate that the formation energy of an interstitial He atom is smaller than that of a substitutional He atom in all hcp rare-earth metals considered. Furthermore, the tetrahedral interstitial position is more favorable than an octahedral position for He defects. The results are compared with those from bcc and fcc metals.展开更多
Using direct current-magnetron sputtering,Helium-trapped Ti films with a He/Ar mixture was studied.The relative helium content,helium depth profiles for the Ti films and crystallization capacity were analyzed by Enhan...Using direct current-magnetron sputtering,Helium-trapped Ti films with a He/Ar mixture was studied.The relative helium content,helium depth profiles for the Ti films and crystallization capacity were analyzed by Enhanced Proton Backscattering Spectrometry(EPBS)and X-ray diffraction(XRD).It was found that helium diffusion enhanced as more helium trapping into Ti films,and the He holding ratios were 95.9%,94.9%,93.9%,82.8% when the Ti films with the He/Ti of concentrations of 9.7 at.%,19.5 at.%,19.7 at.%,48.3 at.% were measured again 4 months later,respectively.The diffraction peaks be-came weak and wider,the peak of(002)plane was shifted to smaller diffraction angles and the relevant interplanar spacing d(hkl)increased gradually as more helium trapping into Ti films.The main peak was made trending to the(101)plane by both higher deposition temperature and more helium trapping.展开更多
文摘We obtained the reaction mechanism of cerium with oxygen by means of density functional theory (DFT) under the explosive or detonation situation. The energy level order of cerium was calculated and the potential energy profile was plotted. The properties of the bonds of all special structures in the reaction path were analyzed using the method of the electron localization function (ELF). The results indicate that the final reaction pathway can be expressed as Ce+O2→ FC→TS→IM→O-Ce-O, and the formation of Ce2O3 has not been found. In addition, the ELF diagram of the final product CeO2 shows that Ce bonds with both O atoms and the bond angles increase significantly.
基金supported by the National Natural Science Foundation of China (Grant No. 10976007)the Fundamental Research Funds for the Central Universities (Grant No. ZYGX2009J040)+1 种基金the Science and Tech-nology Foundation of China Academy of Engineering Physics (Grant No. 2009A0301015)the US Department of Energy, Office of Fusion En-ergy Science (Grant No. DE-AC06-76RLO 1830)
文摘He defect properties in Sc, Y, Gd, Tb, Dy, Ho, Er and Lu were studied using first-principles calculations based on density functional theory. The results indicate that the formation energy of an interstitial He atom is smaller than that of a substitutional He atom in all hcp rare-earth metals considered. Furthermore, the tetrahedral interstitial position is more favorable than an octahedral position for He defects. The results are compared with those from bcc and fcc metals.
基金the China Academy of Engineering Physics(Grant No.2003Z0501)
文摘Using direct current-magnetron sputtering,Helium-trapped Ti films with a He/Ar mixture was studied.The relative helium content,helium depth profiles for the Ti films and crystallization capacity were analyzed by Enhanced Proton Backscattering Spectrometry(EPBS)and X-ray diffraction(XRD).It was found that helium diffusion enhanced as more helium trapping into Ti films,and the He holding ratios were 95.9%,94.9%,93.9%,82.8% when the Ti films with the He/Ti of concentrations of 9.7 at.%,19.5 at.%,19.7 at.%,48.3 at.% were measured again 4 months later,respectively.The diffraction peaks be-came weak and wider,the peak of(002)plane was shifted to smaller diffraction angles and the relevant interplanar spacing d(hkl)increased gradually as more helium trapping into Ti films.The main peak was made trending to the(101)plane by both higher deposition temperature and more helium trapping.
