摘要
采用SCC-DV-Xα方法,首次对NiTi合金表面生成的锐钛矿氧化层中镍的释放行为进行了理论计算.在构造合理团簇模型的基础上,计算出镍离子在锐钛矿(110)和(001)表面扩散的可能性及其强度大小.通过对键级、电荷分布、以及态密度的计算结果进行分析显示,当NiTi合金表面形成锐钛矿TiO2表面膜时,由于镍原子与氧原子之间形成有效的共价键,抑制了表面镍离子的溶出,从理论上验证了在NiTi合金表面制备TiO2锐钛矿氧化膜将有利于提高其生物相容性.
The theoretical calculation of nickel release in anatase oxide layer on NiTi surface is completed by SCC-DV- Xαmeethod. The DV-Xαcluster is a molecular orbital method in which a Slater Xαexchange-correlation potential, Vex, is taken to be function of electron density. The cluster models of anatase are selected and nickel release is researched on anatase （110） and （110） surface respectively. The calculated results of bond order, charge distributing, energy level and partial density of state show nickel release is prohibited by the formation of anatase oxide layer on NiTi alloy surface. It was found from the Mulliken population analysis that the negative charge of 0 atom increases after the formation of anatase oxide layer. It would be difficult that Ni leave anatase surface. Anatase oxide layer on NiTi shape memory alloy surface may prohibit nickel release and would be preferable for increasing its biocompatibilities.
出处
《海南师范大学学报（自然科学版）》
CAS
2008年第2期167-170,共4页
Journal of Hainan Normal University（Natural Science）
基金
国家自然科学基金资助项目(20273012)
海南省教育厅高等学校科研基金资助项目(Hjkj200415)
