Effects of W-doping on formation energy of oxygen vacancy in TiO2
ZHU Linggang1,2, ZHOU Jian1, SUN Zhimei1,2
1. School of Materials Science and Engineering, Beijing University of Aeronautics and Astronautics, Beijing 100083, China;
2. Center for Integrated Computational Materials Engineering, Beijing University of Aeronautics and Astronautics, Beijing 100083, China
Abstract：First-principles calculations were used to study the influence of W-doping on the formation energy of oxygen vacancy in rutile TiO2 oxide, in order to explore the possible effects on the corrosion resistance of Ti alloys by the addition of W which is normally used to strengthen the matrix. It was found that W can increase the formation energy of neighboring oxygen vacancy by nearly 0.7 eV, meaning that it can inhibit the generation of oxygen vacancy and the penetration of oxygen into the matrix effectively, which is beneficial for the oxidation resistance of Ti alloys. For the oxygen-vacancy pairs with different configurations, W can also increase their formation energy, by only 0.2 eV per vacancy; therefore, the positive effects of W will be weakened with the accumulation of oxygen vacancies and the acceleration of the oxidation process. Analysis on the electronic density of states shows that for oxygen-vacancy pairs with various configurations, the energy levels of the states of the unbounded electrons are different, which eventually lead to various formation energies.
祝令刚, 周健, 孙志梅. W掺杂对TiO2中氧空位形成能的影响[J]. 北京航空航天大学学报, 2016, 42(1): 54-58.
ZHU Linggang, ZHOU Jian, SUN Zhimei. Effects of W-doping on formation energy of oxygen vacancy in TiO2. JOURNAL OF BEIJING UNIVERSITY OF AERONAUTICS AND A, 2016, 42(1): 54-58.
[1] LVTJERING G,WILLIAMS J.Titanium[M].Berlin:Springer,2003:29-39.
[2] 祝令刚.Ti和Nb合金中氧化问题的理论研究[D].沈阳:中国科学院金属研究所,2014:2-7. ZHU L G.Theoretical study on the oxidation of Ti and Nb-based alloys[D].Shenyang:Insititute of Metal Research,Chinese Academy of Sciences,2014:2-7(in Chinese).
[3] 张雯,易敏,沈志刚,等.氧化物涂层对航天器材料原子氧剥蚀的防护[J].北京航空航天大学学报,2013,39(8):1074-1078. ZHANG W,YI M,SHEN Z G,et al.Protection against atomic oxygen erosion of oxide coatings for spacecraft materials[J].Journal of Beijing University of Aeronautics and Astronautics,2013,39(8):1074-1078(in Chinese).
[4] CHEN Y S,ROSA C J.High-temperature oxidation of Ti-4.32 wt.% Nb alloy[J].Oxidation of Metals,1980,14(2):147-165.
[5] CHAZE A M,CODDET C.Influence of the nature of alloying elements on the adherence of oxide films formed on titanium alloys[J].Oxidation of Metals,1987,28(2):61-71.
[6] CHAZE A M,CODDET C.Influence of aluminium on the oxidation of titanium between 550 and 750℃[J].Journal of the Less Common Metals,1990,157(1):55-70.
[7] FRARY M,ABKOWITZ S,ABKOWITZ S M,et al.Microstructure and mechanical properties of Ti/W and Ti-6Al-4V/W composites fabricated by powder-metallurgy[J].Materials Science and Engineering:A,2003,344(2):103-112.
[8] CHOE H,ABKOWITZ S M,ABKOWITZ S,et al.Effect of tungsten dissolution on the mechanical properties of Ti-W composites[J].Journal of Alloys and Compounds,2005,390(2):62-66.
[9] CHOE H,ABKOWITZ S M,ABKOWITZ S,et al.Effect of tungsten additions on the mechanical properties of Ti-6Al-4V[J].Materials Science and Engineering:A,2005,396(2):99-106.
[10] KRESSE G,FURTHMULLER J.Efficiency of ab-initio total energy calculations for metals and semiconductors using a plane-wave basis set[J].Computational Materials Science,1996,6(1):15-50.
[11] KRESSE G,FURTHMVLLER J.Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set[J].Physical Review B,1996,54(16):11169-11186.
[12] PERDEW J P,WANG Y.Pair-distribution function and its coupling-constant average for the spin-polarized electron gas[J].Physical Review B,1992,46(20):12947-12954.
[13] BLÖCHL P E.Projector augmented-wave method[J].Physical Review B,1994,50(24):17953-17979.
[14] ZHU L G,HU Q M,YANG R.The effect of electron localization on the electronic structure and migration barrier of oxygen vacancies in rutile[J].Journal of Physics:Condensed Matter,2014,26(5):055602-055608.
[15] IDDIR H,OGUT S,ZAPOL P,et al.Diffusion mechanisms of native point defects in rutile TiO2:Ab initio total-energy calculations[J].Physical Review B,2007,75(1):073203-073206.
2016, Vol. 42 
