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Nanoscale structure of Ti1−xNbyO2 mixed-phase thin films: Distribution of crystal phase and dopants

Published online by Cambridge University Press:  23 January 2012

Paul A. DeSario ,
Jinsong Wu ,
Michael E. Grahm  and
Kimberly A. Gray
Paul A. DeSario
Affiliation:
Department of Civil and Environmental Engineering, Northwestern University, Evanston, Illinois 60208
Jinsong Wu
Affiliation:
Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208
Michael E. Grahm
Affiliation:
Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208
Kimberly A. Gray*
Affiliation:
Department of Civil and Environmental Engineering, Northwestern University, Evanston, Illinois 60208
*
a)Address all correspondence to this author. e-mail: k-gray@northwestern.edu
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Abstract

Transmission electron microscopy (polycrystalline electron diffraction, nanoelectron diffraction, and energy dispersive x-ray spectroscopy) was used to determine the dispersion of crystal phase and Nb dopants in mixed-phase (anatase and rutile) Ti1−xNbyO2 thin films prepared by reactive sputtering. When co-sputtering mixed-phase TiO2 with a dopant, it is unclear how the crystal phases are distributed within thin film structures, what the dominant interfaces are, and how the dopant is distributed within the crystal phases. In the Ti1−xNbyO2 films, anatase and rutile grains were found to be homogeneously dispersed indicating that anatase/rutile interfaces are the dominant interfaces. Anatase/rutile interfaces are a critical feature of mixed-phase materials which impart high reactivity to the composite. Nb homogeneously dispersed at low concentrations, but at high concentrations, Nb segregated in the rutile phase. There is an apparent threshold beyond which Nb segregates according to its higher solubility in rutile due to a better lattice fit.

Keywords

DopantSputteringThin film
Type
Articles
Information
Journal of Materials Research , Volume 27 , Issue 6 , 28 March 2012 , pp. 944 - 950
Copyright
Copyright © Materials Research Society 2012

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References

REFERENCES

1.Li, G.H. and Gray, K.A.: The solid-solid interface: Explaining the high and unique photocatalytic reactivity of TiO2-based nanocomposite materials. Chem. Phys. 339, 173 (2007).CrossRefGoogle Scholar
2.Li, G.H., Chen, L., Graham, M.E., and Gray, K.A.: A comparison of mixed phase titania photocatalysts prepared by physical and chemical methods: The importance of the solid-solid interface. J. Mol. Catal. A: Chem. 275, 30 (2007).CrossRefGoogle Scholar
3.Li, G.H., Ciston, S., Saponjic, Z.V., Chen, L., Dimitrijevic, N.M., Rajh, T., and Gray, K.A.: Synthesizing mixed-phase TiO2 nanocomposites using a hydrothermal method for photo-oxidation and photoreduction applications. J. Catal. 253, 105 (2008).CrossRefGoogle Scholar
4.Chen, L., Graham, M.E., Li, G.H., and Gray, K.A.: Fabricating highly active mixed phase TiO2 photocatalysts by reactive dc magnetron sputter deposition. Thin Solid Films 515, 1176 (2006).CrossRefGoogle Scholar
5.Hurum, D.C., Gray, K.A., Rajh, T., and Thurnauer, M.C.: Recombination pathways in the Degussa P25 formulation of TiO2: Surface versus lattice mechanisms. J. Phys. Chem. B 109, 977 (2005).CrossRefGoogle ScholarPubMed
6.Hurum, D.C., Agrios, A.G., Gray, K.A., Rajh, T., and Thurnauer, M.C.: Explaining the enhanced photocatalytic activity of Degussa P25 mixed-phase TiO2 using EPR. J. Phys. Chem. B 107, 4545 (2003).CrossRefGoogle Scholar
7.Chen, L., Graham, M.E., and Gray, K.A.: Nitrogen stabilized reactive sputtering of optimized TiO2-x photocatalysts with visible light reactivity. J. Vac. Sci. Technol. A 27, 712 (2009).CrossRefGoogle Scholar
8.DeSario, P.A., Chen, L., Graham, M.E., and Gray, K.A.: Non-stoichiometric mixed-phase titania thin films: Red-shifted photoresponse and enhanced reactivity. J. Vac. Sci. Technol. A 29 (2011).CrossRefGoogle Scholar
9.DeSario, P.A., Graham, M.E., Gelfand, R.M., and Gray, K.A.: The effect of Nb substitution on the synthesis and photo-response of TiO2 thin films prepared by direct current magnetron sputtering. Thin Solid Films 519, 3562 (2011).CrossRefGoogle Scholar
10.Yang, M., Kim, D., Jha, H., Lee, K., Paul, J., and Schmuki, P.: Nb doping of TiO2 nanotubes for an enhanced efficiency of dye-sensitized solar cells. Chem. Commun. 47, 2032 (2011).Google ScholarPubMed
11.Kurita, D., Ohta, S., Sugiura, K., Ohta, H., and Koumoto, K.: Carrier generation and transport properties of heavily Nb-doped anatase TiO2 epitaxial films at high temperatures. J. Appl. Phys. 100, 096105 (2006).CrossRefGoogle Scholar
12.Furubayashi, Y., Hitosugi, T., Yamamoto, Y., Inaba, K., Kinoda, G., Hirose, Y., Shimada, T., and Hasegawa, T.: A transparent metal: Nb-doped anatase TiO2. Appl. Phys. Lett. 86, 252101 (2005).CrossRefGoogle Scholar
13.Sacerdoti, M., Dalconi, M.C., Carotta, M.C., Cavicchi, B., Ferroni, M., Colonna, S., and Di Vona, M.L.: XAS investigation of tantalum and niobium in nanostructured TiO2 anatase. J. Solid State Chem. 177, 1781 (2004).CrossRefGoogle Scholar
14.Arbiol, J., Cerda, J., Dezanneau, G., Cirera, A., Peiro, F., Cornet, A., and Morante, J.R.: Effects of Nb doping on the TiO2 anatase-to-rutile phase transition. J. Appl. Phys. 92, 853 (2002).CrossRefGoogle Scholar
15.Gillispie, M.A., van Hest, M., Dabney, M.S., Perkins, J.D., and Ginley, D.S.: Rf magnetron sputter deposition of transparent conducting Nb-doped TiO2 films on SrTiO3. J. Appl. Phys. 101, 033125 (2007).CrossRefGoogle Scholar
16.Gao, Y.: In-situ IR and spectroscopic ellipsometric analysis of growth process and structural properties of Ti1-xNbxO2 thin films by metal-organic chemical vapor deposition. Thin Solid Films 346, 73 (1999).CrossRefGoogle Scholar
17.Depero, L.E., Sangaletti, L., Allieri, B., Bontempi, E., Salari, R., Zocchi, M., Casale, C., and Notaro, M.: Niobium-titanium oxide powders obtained by laser-induced synthesis: Microstructure and structure evolution from diffraction data. J. Mater. Res. 13, 1644 (1998).CrossRefGoogle Scholar
18.Morris, D., Dou, Y., Rebane, J., Mitchell, C.E.J., Egdell, R.G., Law, D.S.L., Vittadini, A., and Casarin, M.: Photoemission and STM study of the electronic structure of Nb-doped TiO2. Phys. Rev. B 61, 13445 (2000).CrossRefGoogle Scholar
19.Sheppard, L., Bak, T., Nowotny, J., Sorrell, C.C., Kumar, S., Gerson, A.R., Barnes, M.C., and Ball, C.: Effect of niobium on the structure of titanium dioxide thin films. Thin Solid Films 510, 119 (2006).CrossRefGoogle Scholar
20.Furubayashi, Y., Yamada, N., Hirose, Y., Yamamoto, Y., Otani, M., Hitosugi, T., Shimada, T., and Hasegawa, T.: Transport properties of d-electron-based transparent conducting oxide: Anatase Ti1-xNbxO2. J. Appl. Phys. 101, 093705 (2007).CrossRefGoogle Scholar
21.Furubayashi, Y., Hitosugi, T., Yamamoto, Y., Hirose, Y., Kinoda, G., Inaba, K., Shimada, T., and Hasegawa, T.: Novel transparent conducting oxide: Anatase Ti1-xNbxO2. Thin Solid Films 496, 157 (2006).CrossRefGoogle Scholar
22.Ruiz, A.M., Dezanneau, G., Arbiol, J., Cornet, A., and Morante, J.R.: Insights into the structural and chemical modifications of Nb additive on TiO2 nanoparticles. Chem. Mater. 16, 862 (2004).CrossRefGoogle Scholar
23.Gao, Y., Liang, Y., and Chambers, S.A.: Synthesis and characterization of Nb-doped TiO2(110) surfaces by molecular beam epitaxy. Surf. Sci. 348, 17 (1996).CrossRefGoogle Scholar
24.Chambers, S.A., Gao, Y., Thevuthasan, S., Liang, Y., Shivaparan, N.R., and Smith, R.J.: Molecular beam epitaxial growth and characterization of mixed (Ti,Nb)O2 rutile films on TiO2(100). J. Vac. Sci. Technol. A 14, 1387 (1996).CrossRefGoogle Scholar
25.Valigi, M., Cordischi, D., Minelli, G., Natale, P., Porta, P., and Keijzers, C.P.: A structural, thermogravimetric, magnetic, electron-spin resonance, and optical reflectance study of the NbO2-TiO2 system. J. Solid State Chem. 77, 255 (1988).CrossRefGoogle Scholar
26.Ghicov, A., Yamamoto, M., and Schmuki, P.: Lattice widening in niobium-doped TiO2 nanotubes: Efficient ion intercalation and swift electrochromic contrast. Angew. Chem. Int. Ed. 47, 7934 (2008).CrossRefGoogle ScholarPubMed
27.Chambers, S.A., Gao, Y., Kim, Y.J., Henderson, M.A., Thevuthasan, S., Wen, S., and Merkle, K.L.: Geometric and electronic structure of epitaxial NbxTi1-xO2 on TiO2(110). Surf. Sci. 365, 625 (1996).CrossRefGoogle Scholar
28.Das Mulmi, D., Sekiya, T., Kamiya, N., Kurita, S., Murakami, Y., and Kodaira, T.: Optical and electric properties of Nb-doped anatase TiO2 single crystal. J. Phys. Chem. Solids 65, 1181 (2004).CrossRefGoogle Scholar
29.Sproul, W.D., Graham, M.E., Wong, M.S., Lopez, S., Li, D., and Scholl, R.A.: Reactive direct-current magnetron sputtering of aluminium-oxide coatings. J. Vac. Sci. Technol. A 13, 1188 (1995).CrossRefGoogle Scholar
30.Chen, L., Graham, M.E., Li, G.H., Gentner, D.R., Dimitrijevic, N.M., and Gray, K.A.: Photoreduction of CO2 by TiO2 nanocomposites synthesized through reactive direct current magnetron sputter deposition. Thin Solid Films 517, 5641 (2009).CrossRefGoogle Scholar
31.Sakata, K.: Study of phase transition in NbxTi1-xO2. J. Phys. Soc. Jpn. 26, 1067 (1969).CrossRefGoogle Scholar
32.Marinder, B.O. and Magneli, A.: Rutile-type phases in some systems of mixed transition metal dioxides. Acta Chem. Scand. 12, 1345 (1958).CrossRefGoogle Scholar
33.Antonio, M.R., Song, I., and Yamada, H.: Coordination and valence of niobium in TiO2–NbO2 solid-solutions through x-ray absorption-spectroscopy. J. Solid State Chem. 93, 183 (1991).CrossRefGoogle Scholar
34.Zhang, C.N., Ikeda, M., Uchikoshi, T., Li, J.G., Watanabe, T., and Ishigaki, T.: High-concentration niobium (V) doping into TiO2 nanoparticles synthesized by thermal plasma processing. J. Mater. Res. 26, 658 (2011).CrossRefGoogle Scholar
35.Zhang, H.Z. and Banfield, J.F.: Phase transformation of nanocrystalline anatase-to-rutile via combined interface and surface nucleation. J. Mater. Res. 15, 437 (2000).CrossRefGoogle Scholar
36.Gouma, P.I. and Mills, M.J.: Anatase-to-rutile transformation in titania powders. J. Am. Ceram. Soc. 84, 619 (2001).CrossRefGoogle Scholar
37.Aldabergenova, S.B., Ghicov, A., Albu, S., Macak, J.M., and Schmuki, P.: Smooth titania nanotubes: Self-organization and stabilization of anatase phase. J. Non-Cryst. Solids 354, 2190 (2008).CrossRefGoogle Scholar
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