Abstract
Cobalt (Co)-doped zinc oxide (ZnO) diluted magnetic semiconductor thin films were grown using a low-cost spray pyrolysis technique. X-ray diffraction (XRD) studies show that the films crystallize in the pure wurtzite structure. No evidence of the formation of secondary phases like Co clusters, CoO or Co3O4 were detected from XRD studies. Scanning electron microscopy studies show uniform growth over the substrates and energy dispersive analysis of X-ray studies confirm the presence of Co in ZnO. The absorption bands peaked at the wavelength ~658, 613 and 567 nm in the optical transmission spectra show that the Co enters the tetrahedral sites of the wurtzite structure in the desired Co2+ oxidation state. The strong optical absorption in the band tail region indicates the existence of magnetic ion-induced charge-transfer states (CTSs) just below the band edge. The photoluminescence from ZnO is found to be completely quenched on Co doping due to the occurrence of CTSs. Magnetic studies show that all the films possess ferromagnetism at room temperature with Curie temperature well above the room temperature. The grown films have potential applications in spintronic devices.
Similar content being viewed by others
References
Zutic I, Fabian J and Sarma S D 2004 Rev. Mod. Phys. 76 323
Ohno H, Shen A, Matsukura F, Oiwa A, Endo A, Katsumoto S et al 1996 Appl. Phys. Lett. 69 363
Dietl T, Ohno H, Matsukura F, Cibert J and Ferrand D 2000 Science 287 1019
Sato K and Katayama-Yoshida H 2001 Jpn. J. Appl. Phys. 40 L334
Yin Z, Chen N, Chai C and Yang F 2004 J. Appl. Phys. 96 5093
Huang H H, Yang C A, Huang P H, Lai C H, Chin T S, Huang H E et al 2007 J. Appl. Phys. 101 09H116
Pal B and Giri P K 2010 J. Appl. Phys. 108 084322
Yang S, Man B Y, Liu M, Chen C S, Gao X G, Wang C C et al 2010 Physica B 405 4027
Dhruvashi and Shishodia P K 2016 Thin Solid Films 612 55
Simimol A, Anappara A A, Greulich-Weber S, Chowdhury P and Barshiliaa H C 2015 J. Appl. Phys. 117 214310
Yang S, Lv R, Wang C, Liu Y and Song Z 2013 J. Alloys Comp. 579 628
Jin Z, Fukumura T and Kawasaki M 2010 Appl. Phys. Lett. 78 3824
Singh P, Deepak, Goyal R N, Pandey A K and Kaur D 2008 J. Phys.: Condens. Matter 20 315005
Zhao L L, Wang J Y, Wang X L, Cheng Z X, Wang J, Yin N et al 2015 J. Alloys Comp. 628 303
Kim K J and Park Y R 2002 Appl. Phys. Lett. 81 1420
Kittilstved K R, Liu W K and Gamelin D R 2006 Nat. Mater. 5 291
Yamamoto S 2012 J. Appl. Phys. 111 094310
Noras J M and Allen J W 1980 J. Phys. C 13 3511
Heitz R, Hoffmann A and Broser I 1993 Phys. Rev. B 48 8672
Bishop S G, Robbins D J and Dean P J 1980 Solid State Commun. 33 119
Muller B, Roussos G and Schulz H J 1985 J. Cryst. Growth 72 360
Juhl A, Hoffmann A, Bimberg D and Schulz H J 1987 Appl. Phys. Lett. 50 1292
Liu W K, Salley G M and Gamelin D R 2005 J. Phys. Chem. B 109 14486
Fleurov V N and Kikoin K A 1982 Solid State Commun. 42 353
Mizokawa T and Fujimori A 1993 Phys. Rev. B 48 14150
Blinowski J, Kacman P and Dietl T 2002 Mater Res. Soc. Symp. Proc. 690 109
Xiao Z, Matsui H, Hasuike N, Harima H and Tabata H 2008 J. Appl. Phys. 103 043504
Zheng H 1995 Physica B 212 125
Powell R J and Spicer W E 1970 Phys. Rev. B 2 2182
Thakur V, Verma U P and Rajaram P 2014 Electron. Mater. Lett. 10 1143
Beaulac R, Archer P I and Gamelin D R 2008 J. Solid State Chem. 181 1582
Xiao Z, Matsui H, Katayama K, Miyajima K, Itoh T and Tabata H 2010 J. Appl. Phys. 108 13502
Khan Z A and Ghosh S 2011 Appl. Phys. Lett. 99 042504
Sarma S D, Hwang E H and Kaminski A 2003 Phys. Rev. B 67 155201
Coey J M D, Venkatesan M and Fitzgerald C B 2005 Nat. Mater. 4 173
Petit L, Schulthess T C, Svane A, Temmerman W M and Szotek Z 2004 Res. Soc. Symp. Proc. 825E 9
Wang Q, Sun Q, Jena P and Kawazoe Y 2004 Phys. Rev. B 70 052408
Acknowledgements
We are grateful to IIC, IIT Roorkee and SAIF, Punjab University, Chandigarh, for providing experimental facilities like XRD, SEM/EDAX and superconducting quantum interference device magnetometer.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Thakur, V., Verma, U. Growth of Co-doped ZnO thin films exhibiting room temperature ferromagnetism using a low-cost spray pyrolysis technique. Bull Mater Sci 45, 32 (2022). https://doi.org/10.1007/s12034-021-02614-z
Received:
Accepted:
Published:
DOI: https://doi.org/10.1007/s12034-021-02614-z