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Investigations of the valence states, cobalt ion distribution, and defect structures in Co-doped ITO films

Published online by Cambridge University Press:  21 June 2018

Zhen Lin ,
Wenlong Lai ,
Zhonghua Wu ,
Jiwen Liu  and
Yukai An
Zhen Lin
Affiliation:
School of Material Science and Engineering, Tianjin University of Technology, Tianjin 300384, China
Wenlong Lai
Affiliation:
School of Material Science and Engineering, Tianjin University of Technology, Tianjin 300384, China
Zhonghua Wu
Affiliation:
Beijing Synchrotron Radiation Facility (BSRF), Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 1040049, China
Jiwen Liu
Affiliation:
Key Laboratory of Display Materials and Photoelectric Devices, Ministry of Education, Tianjin Key Laboratory for Photoelectric Materials and Devices, National Demonstration Center for Experimental Function Materials Education, School of Material Science and Engineering, Tianjin University of Technology, Tianjin 300384, China
Yukai An*
Affiliation:
Key Laboratory of Display Materials and Photoelectric Devices, Ministry of Education, Tianjin Key Laboratory for Photoelectric Materials and Devices, National Demonstration Center for Experimental Function Materials Education, School of Material Science and Engineering, Tianjin University of Technology, Tianjin 300384, China
*
a)Address all correspondence to this author. e-mail: [email protected]
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Abstract

The valence states, the distribution of Co ions, and defect structures in the Co-doped ITO films with Co concentrations of 5–13 at.% were examined by X-ray absorption spectroscopy (XAS) at Co, K, and L-edges. The structural analyses and ab initio calculations reveal that the Co atoms are substantially incorporated into the ITO lattice and form cobalt–vacancy complexes, while partial formation of Co0 species is observed for all the films. The analyses of Co–K edge XAS reveal that the Co–O bond length RCo–O is shortened and the corresponding Debye–Waller factor (σ2) obviously increases with Co doping, implying the relaxation of oxygen environment around the substitutional Co ions. The qualitative fitting of Co L3-edge XAS further confirms the coexistence of Co0 and Co2+ in the films. The Co atoms mainly occupy the substitutional sites of In2O3 lattices with the metallic Co clusters being about 20–43 at.% for the 5, 7, and 8.5 at.% Co-doped ITO films. However, a significant fraction (∼57 at.%) of metallic Co clusters is found in the 13 at.% Co-doped ITO film.

Keywords

ITO filmCo dopinglocal structureCo clusters
Type
Article
Information
Journal of Materials Research , Volume 33 , Issue 16 , 28 August 2018 , pp. 2336 - 2341
Copyright
Copyright © Materials Research Society 2018 

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References

REFERENCES

Žutić, I., Fabian, J., and Sarma, S.D.: Spintronics: Fundamentals and applications. Rev. Mod. Phys. 76, 323 (2004).CrossRefGoogle Scholar
Karamat, S., Rawat, R.S., Lee, P., Tan, T.L., Ke, C., Chen, R., and Sun, H.D.: Ferromagnetic signature in vanadium doped ZnO thin films grown by pulsed laser deposition. J. Mater. Res. 31, 3223–3229 (2016).CrossRefGoogle Scholar
Dietl, T., Ohno, H., Matsukura, F., Cibert, J., and Ferrand, D.: Zener model description of ferromagnetism in zinc-blende magnetic semiconductors. Science 287, 1019 (2000).CrossRefGoogle ScholarPubMed
Wang, D.D., Xing, G.Z., Yan, F., Yan, Y.S., and Li, S.: Ferromagnetic (Mn, N)-codoped ZnO nanopillars array: Experimental and computational insights. Appl. Phys. Lett. 104, 022412 (2014).CrossRefGoogle Scholar
Jayalakshmi, G. and Balasubramaniana, T.: Realization of enhanced room temperature ferromagnetism in pure and V-doped ZnO films on TOP functionalization. J. Mater. Res. 29, 158–165 (2014).CrossRefGoogle Scholar
Hu, W., Hayashi, K., Fukumura, T., Akagi, K., Tsukada, M., Happo, N., Hosokawa, S., Ohwada, K., Takahasi, M., Suzuki, M., and Kawasaki, M.: Spontaneous formation of suboxidic coordination around Co in ferromagnetic rutile Ti0.95Co0.05O2 film. Appl. Phys. Lett. 106, 222403 (2015).CrossRefGoogle Scholar
Prajapati, B., Kumar, S., Kumar, M., Chatterjee, S., and Ghos, A.K.: Investigation of the physical properties of Fe:TiO2-diluted magnetic semiconductor nanoparticles. J. Mater. Chem. C 5, 4257–4267 (2017).CrossRefGoogle Scholar
Myagkov, V.G., Tambasov, I.A., Bayukov, O.A., Zhigalov, V.S., Bykova, L.E., Mikhlin, Y.L., Volochaev, M.N., and Bondarenko, G.N.: Solid state synthesis and characterization of ferromagnetic nanocomposite Fe–In2O3 thin films. J. Alloys Compd. 612, 189–194 (2014).CrossRefGoogle Scholar
Yan, S.M., Qiao, W., Zhong, W., Au, C.T., and Dou, Y.W.: Effects of site occupancy and valence state of Fe ions on ferromagnetism in Fe-doped In2O3 magnetic semiconductor. Appl. Phys. Lett. 104, 062404 (2014).CrossRefGoogle Scholar
Park, C.Y., You, C.Y., Jeon, K.R., and Shin, S.C.: Charge-carrier mediated ferromagnetism in Mo-doped In2O3 films. Appl. Phys. Lett. 100, 222409 (2012).CrossRefGoogle Scholar
Li, S.C., Ren, P., Zhao, B.C., Xia, B., and Wang, L.: Room temperature ferromagnetism of bulk polycrystalline (In0.85−xSnxFe0.15)2O3: Charge carrier mediated or oxygen vacancy mediated? Appl. Phys. Lett. 95, 102101 (2009).CrossRefGoogle Scholar
Xing, G.Z., Yi, J.B., Wang, D.D., Liao, L., Yu, T., Shen, Z.X., Huan, C.H.A., Sun, T.C., Ding, J., and Wu, T.: Strong correlation between ferromagnetism and oxygen deficiency in Cr-doped In2O3−δ nanostructures. Phys. Rev. B 79, 174406 (2009).CrossRefGoogle Scholar
Subías, G., Stankiewicz, J., Villuendas, F., Lozano, M.P., and García, J.: Local structure study of Co-doped indium oxide and indium–tin oxide thin films using X-ray absorption spectroscopy. Phys. Rev. B 79, 094118 (2009).CrossRefGoogle Scholar
Jiang, F.X., Xi, S.B., Ma, R.R., Qin, X.F., Fan, X.C., Zhang, M.G., Zhou, J.Q., and Xu, X.H.: Room-temperature ferromagnetism in Fe/Sn-codoped In2O3 powders and thin films. Chin. Phys. Lett. 30, 047501 (2013).CrossRefGoogle Scholar
Kohiki, S., Murakawa, Y., Hori, K., Shimooka, H., Tajiri, T., Deguchi, H., Oku, M., Arai, M., Mitome, M., and Bando, Y.: Magnetic behavior of Fe doped In2O3. Jpn. J. Appl. Phys. 44, L979 (2005).CrossRefGoogle Scholar
Kimura, H., Fukumura, T., Kawasaki, M., Inaba, K., Hasegawa, T., and Koinuma, H.: Rutile-type oxide-diluted magnetic semiconductor: Mn-doped SnO2. Appl. Phys. Lett. 80, 94–96 (2002).CrossRefGoogle Scholar
Gupta, A., Cao, H., Parekh, K., Rao, K.V., Raju, A.R., and Waghmare, U.V.: Room temperature ferromagnetism in transition metal (V, Cr, Ti) doped In2O3. J. Appl. Phys. 101, 09N513 (2007).CrossRefGoogle Scholar
Ravel, B. and Newville, M.: ATHENA, ARTEMIS, HEPHAESTUS: Data analysis for X-ray absorption spectroscopy using IFEFFIT. J. Synchrotron Radiat. 12, 537–541 (2005).CrossRefGoogle ScholarPubMed
Parent, P., Dexpert, H., Tourillon, G., and Grimal, J.M.: Structural study of tin-doped indium oxide thin films using X-ray absorption spectroscopy and X-ray diffraction. I-description of the indium site. II-tin environment. J. Electrochem. Soc. 139, 276–285 (1992).CrossRefGoogle Scholar
Magnuson, M., Butorin, S.M., Guo, J-H., and Mordgren, J.: Electronic structure investigation of CoO by means of soft X-ray scattering. Phys. Rev. B 65, 205106 (2002).CrossRefGoogle Scholar
Valencia, S., Gaupp, A., Gudat, W., Abad, L., Balcells, L., Cavallaro, A., Martínez, B., and Palomares, F.J.: Mn valence instability in La2/3Ca1/3MnO3 thin films. Phys. Rev. B 73, 104402 (2006).CrossRefGoogle Scholar