Switching in structural, optical, and magnetic properties of self-assembled Co-doped ZnO: effect of Co-concentration

  • Richa Bhargava
  • Prashant K. Sharma
  • Sushant Singh
  • Mohit Sahni
  • Avinash C. Pandey
  • Naresh Kumar


Here, we report on the self-assembled Co-doped ZnO nanoparticles synthesized by using sol–gel technique. It has been observed that when Co is introduced in the solution, nanoparticles arrange themselves into a particular pattern. This self-assembly of Zn1−xCoxO, were found to be consistent with the change in Co-doping concentration. Using electron microscopy these systems were studied to confirm the assembly formation with doping. Optical study of these assemblies suggests the decrease in direct band gap of these systems with the increase in doping concentration. In addition to it, the Urbach energy was found to be increased, indicating the redistribution of states in between conduction and valence band with doping. Magnetic measurement shows the introduction of paramagnetic behavior with Co-doping in this self-assembled Co-doped ZnO.


Co3O4 Room Temperature Ferromagnetism Urbach Energy Zinc Nitrate Hexahydrate Cobalt Nitrate Hexahydrate 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


  1. 1.
    S.C. Navale, V. Ravi, I.S. Mulla, Investigations on Ru doped ZnO: strain calculations and gas sensing study. Sens. Actuators B 139, 466–470 (2009)CrossRefGoogle Scholar
  2. 2.
    C.J. Cong, J.H. Hong, K.L. Zhanga, Effect of atmosphere on the magnetic properties of the Co-doped ZnO magnetic semiconductors. Mater. Chem. Phys. 113, 435–440 (2009)CrossRefGoogle Scholar
  3. 3.
    R. Bhargava, P.K. Sharma, R.K. Dutta, S. Kumar, A.C. Pandey, N. Kumar, Influence of Co-doping on the thermal, structural, and optical properties of sol–gel derived ZnO nanoparticles. Mater. Chem. Phys. 120, 393–398 (2010)CrossRefGoogle Scholar
  4. 4.
    R. Bhargava, P.K. Sharma, A.K. Chawla, S. Kumar, R. Chandra, A.C. Pandey, N. Kumar, Variation in structural, optical and magnetic properties of Zn1−xCrxO (x = 0.0, 0.10, 0.15, and 0.20) nanoparticles: role of dopant concentration on non-saturation of magnetization. Mater. Chem. Phys. 125, 664–671 (2011)CrossRefGoogle Scholar
  5. 5.
    S. Thota, T. Dutta, J. Kumar, On the sol–gel synthesis and thermal, structural, and magnetic studies of transition metal (Ni, Co, Mn) containing ZnO powders. J. Phys. Condens. Matter 18, 2473 (2006)CrossRefGoogle Scholar
  6. 6.
    H. Yang, S. Nie, Preparation and characterization of Co-doped ZnO nanomaterials. Mater. Chem. Phys. 114, 279–282 (2009)CrossRefGoogle Scholar
  7. 7.
    D. Gao, Y. Xu, Z. Zhang, H. Gao, D. Xue, Room temperature ferromagnetism of Cu doped ZnO nanowire arrays. J. Appl. Phys. 105, 063903 (2009)CrossRefGoogle Scholar
  8. 8.
    A. Parra-Palomino, O. Perales-Perez, R. Singhal, M. Tomar, J. Hwang, P.M. Voyles, Structural, optical, and magnetic characterization of monodisperse Fe-doped ZnO nanocrystals. J. Appl. Phys. 103, 07D121 (2008)CrossRefGoogle Scholar
  9. 9.
    E. Liu, Y. He, J.Z. Jiang, Ferromagnetism induced by defect complex in Co-doped ZnO. Appl. Phys. Lett. 93, 132506 (2008)CrossRefGoogle Scholar
  10. 10.
    P.K. Sharma, R.K. Dutta, A.C. Pandey, Alteration of magnetic and optical properties of ultrafine dilute magnetic semiconductor ZnO:Co2+ nanoparticles. J. Colloid Interface Sci. 345, 149–153 (2010)CrossRefGoogle Scholar
  11. 11.
    L. Yao, M. Zheng, C. Li, L. Ma, W. Shen, Facile synthesis of superhydrophobic surface of ZnO nanoflakes: chemical coating and UV induced wettability conversion. Nanoscale Res. Lett. 7, 216 (2012)CrossRefGoogle Scholar
  12. 12.
    W. Baiqi, S. Xudong, F. Qiang, J. Iqbal, L. Yan, F. Honggang, Y. Dapeng, Photoluminescence properties of Co-doped ZnO nanorods array fabricated by the solution method. Phys. E 41, 413–417 (2009)CrossRefGoogle Scholar
  13. 13.
    M.K. Patra, K. Manzoor, M. Manoth, S.R. Vadera, N. Kumar, Studies on structural and magnetic properties of Co-doped pyramidal ZnO nanorods synthesized by solution growth technique. J. Phys. Chem. Solids 70, 659–664 (2009)CrossRefGoogle Scholar
  14. 14.
    M.A. Majeed Khan, M.W. Khan, M. Alhoshan, M.S. AlSalhi, A.S. Aldwayyan, Influences of Co doping on the structural and optical properties of ZnO nanostructured. Appl. Phys. A 100, 45–51 (2010)CrossRefGoogle Scholar
  15. 15.
    N. Hasuike, K. Nishio, H. Katoh, A. Suzuki, T. Isshiki, K. Kisoda, H. Harima, Structural and electronic properties of ZnO polycrystals doped with Co. J. Phys. Condens. Matter 21, 064215 (2009)CrossRefGoogle Scholar
  16. 16.
    J.H. Yang, J.H. Zheng, H.J. Zhai, L.L. Yang, Low temperature hydrothermal growth and optical properties of ZnO nanorods. Cryst. Res. Technol. 44, 87–91 (2009)CrossRefGoogle Scholar
  17. 17.
    S.C. Navale, I.S. Mulla, Photoluminescence and gas sensing study of nanostructured pure and Sn doped ZnO. Mater. Sci. Eng. C 29, 1317–1320 (2008)CrossRefGoogle Scholar
  18. 18.
    E. Gür, S. Tüzemen, K. Meral, Y. Onganer, Oxygen deficiency effects on recombination lifetime and photoluminescence characteristics of ZnO thin films; correlation with crystal structure. Appl. Phys. A 94, 549–554 (2009)CrossRefGoogle Scholar
  19. 19.
    P.V. Radovanovic, C.J. Barrelet, S. Gradecak, F. Qian, C.M. Lieber, General synthesis of manganese-doped II–VI and III–V semiconductor nanowires. Nano Lett. 5, 1407–1411 (2005)CrossRefGoogle Scholar
  20. 20.
    S. Singh, E.S. Kumar, M.S.R. Rao, Microstructural, optical and electrical properties of Cr-doped ZnO. Scripta Mater. 58, 866–869 (2008)CrossRefGoogle Scholar
  21. 21.
    A.K. Srivastava, M. Deepa, N. Bahadur, M.S. Goyat, Influence of Fe doping on nanostructures and photoluminescence of sol–gel derived ZnO. Mater. Chem. Phys. 114, 194–198 (2009)CrossRefGoogle Scholar
  22. 22.
    F. Gu, C. Li, Y. Hu, L. Zhang, Synthesis and optical characterization of Co3O4 nanocrystals. J. Cryst. Growth 304, 369–373 (2007)CrossRefGoogle Scholar
  23. 23.
    J. Pal, P. Chauhan, Study of physical properties of cobalt oxide (Co3O4) nanocrystals. Mater. Charact. 61, 575–579 (2010)CrossRefGoogle Scholar
  24. 24.
    M. Caglar, F. Yakuphanoglu, Structural and optical properties of copper doped ZnO films derived by sol–gel. Appl. Surf. Sci. 258, 3039–3044 (2012)CrossRefGoogle Scholar
  25. 25.
    S. Ilican, Y. Caglar, M. Caglar, F. Yakuphanoglu, Structural, optical and electrical properties of F-doped ZnO nanorod semiconductor thin films deposited by sol–gel process. Appl. Surf. Sci. 255, 2353–2359 (2008)CrossRefGoogle Scholar
  26. 26.
    R.Y. Sato-Berru, A. Vazquez-Olmos, A.L. Fernandez-Osorio, S. Sotres-Martnez, Micro-Raman investigation of transition-metal-doped ZnO nanoparticles. J. Raman Spectrosc. 38, 1073–1076 (2007)CrossRefGoogle Scholar
  27. 27.
    R. Bhargava, P.K. Sharma, S. Kumar, A.C. Pandey, N. Kumar, Raman investigations of Zn1−xCoxO nanocrystals: role of starting precursors on vibrational properties. J. Raman Spectrosc. 42, 1802–1807 (2011)CrossRefGoogle Scholar
  28. 28.
    K.R. Kittilstved, D.A. Schwartz, A.C. Tuan, S.M. Heald, S.A. Chambers, D.R. Gamelin, Direct kinetic correlation of carriers and ferromagnetism in Co2+: ZnO. Phys. Rev. Lett. 97, 037203 (2006)CrossRefGoogle Scholar
  29. 29.
    T.F. Shi, S.Y. Zhu, Z.H. Sun, S.Q. Wei, W.H. Liu, Structures and magnetic properties of wurtzite Zn1−xCoxO dilute magnetic semiconductor nanocomposites. Appl. Phys. Lett. 90, 102108 (2007)CrossRefGoogle Scholar
  30. 30.
    X.Y. Zhou, S.H. Ge, D.S. Yao, Y.L. Zuo, Y.H. Xiao, Effect of thermal treatment on room-temperature ferromagnetism in Co-doped ZnO powders. Phys. B 403, 3336–3339 (2008)CrossRefGoogle Scholar
  31. 31.
    J.H. Yang, L.Y. Zhao, X. Ding, L.L. Yang, Y.J. Zhang, Y.X. Wang, H.L. Liu, Magnetic properties of Co-doped ZnO prepared by sol–gel method. Mater. Sci. Eng. B 162, 143–146 (2009)CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 2013

Authors and Affiliations

  • Richa Bhargava
    • 1
  • Prashant K. Sharma
    • 2
  • Sushant Singh
    • 1
  • Mohit Sahni
    • 1
  • Avinash C. Pandey
    • 3
  • Naresh Kumar
    • 1
  1. 1.Department of PhysicsMotilal Nehru National Institute of TechnologyAllahabadIndia
  2. 2.Department of Applied PhysicsIndian School of MinesDhanbadIndia
  3. 3.Nanotechnology Application CenterUniversity of AllahabadAllahabadIndia

Personalised recommendations