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摘要
To improve the oxidation resistance of Hafnium carbide (HfC) surface, we investigated the adsorption of atomic oxygen on the silicon-doped HfC (0 0 1) surface by first principles. The O/HfC (0 0 1) system was also calculated for comparison. The (root 2 x root 2) R45 degrees supercell was constructed to calculate the adsorption. In calculations, we treated the exchange and correlation potential with the revised version of the Perdew-Burke-Ernzerhof generalized-gradient approximation (GGA-RPBE). Our data demonstrate that the preference adsorption site for oxygen atom is the 4-fold hollow site on the silicon-doped HfC (0 0 1) surface. The oxygen on the silicon-doped surface receives more charges from silicon atoms than that in O/HfC (0 0 1) from carbon atoms. The Si-O bonds exhibit ionic and covalent characteristics, while the C-O bond exhibits primarily covalence. And the covalence of Si-Hf bonds is stronger than that of C-Hf bonds. The strong Si-O and Si-Hf bonds indicate the strong interactions of oxygen with the silicon-doped surface. The strong interactions can explain the possibility of improving the oxidation resistance of HfC surface via doping silicon.
- 出版日期2011-6
- 单位四川轻化工大学
