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Room temperature magnetization in Co-doped anatase phase of TiO2

Published online by Cambridge University Press:  31 January 2013

Masoud Karimipour*
Affiliation:
Department of Physics, Vali-e-Asr University of Rafsanjan, 77139-36417 Rafsanjan, Iran Department of Physics and Astronomy, Uppsala University, Box 516, SE-75120 Uppsala, Sweden
Maxwel Joel Mageto
Affiliation:
Department of Engineering Sciences, Ångström Laboratory, Uppsala University, P.O. Box 534, SE-75121 Uppsala, Sweden Department of Physics, Moi University, P.O. Box 1125, Eldoret, Kenya
Reyhaneh Etefagh
Affiliation:
Nano research Centre, Faculty of Basic Sciences, Ferdowsi University of Mashhad, Mashhad, Iran
Elahe Azhir
Affiliation:
Nano research Centre, Faculty of Basic Sciences, Ferdowsi University of Mashhad, Mashhad, Iran
Mghendi Mwamburi
Affiliation:
Department of Physics, Moi University, P.O. Box 1125, Eldoret, Kenya
Zareh Topalian
Affiliation:
Department of Engineering Sciences, Ångström Laboratory, Uppsala University, P.O. Box 534, SE-75121 Uppsala, Sweden
*
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Abstract

CoxTi1–xO2 films were deposited by spray pyrolysis technique on Si(1 0 0) substrates at 475 °C. A hydro-alcoholic solution containing titanium (iv) isopropoxide and Co(NO3)2 with various Co doping levels from x = 0–0.015 in solution was used as spray solution. Grazing incident angle of X-ray diffraction illustrates that the CoxTi1–xO2 films are single phase and polycrystal with mixed orientations. Study of surface morphology of the films by atomic force microscope reveals that the annealing atmosphere does not significantly affect the grain size and the microstructure of the films. This study provides further insight into the importance of annealing atmosphere on magnetization of the films. Room temperature magneto-optical Kerr measurement was employed in polar mode. A hysteresis loop and a paramagnetic behavior have been recorded for samples annealed in H2 ambient gas and air, respectively. Chemical composition analysis by X-ray photo-electron spectroscopy showed that Co atoms are bounded to oxygen and no metallic clusters are present. Moreover, it indicates the formation of high spin Co2+ for the sample x = 0.008 annealed in H2 ambient gas. The origin of magnetization can be attributed to the contribution of oxygen vacancies in the spin polarization of the structure.

Type
Research Article
Copyright
© EDP Sciences, 2013

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References

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