Local structure investigation of Ni doped ZnO thin films by X-ray absorption spectroscopy

Publication date: 1 February 2018
Source:Thin Solid Films, Volume 647
Author(s): Ashok Kumar Yadav, S. Maidul Haque, Rajnarayan De, Nimai Pathak, D.K. Shukla, R.J. Choudhary, D.M. Phase, S.N. Jha, D. Bhattacharyya
Radio Frequency magnetron sputtering technique has been used to prepare Ni doped ZnO thin films with varying Ni doping concentration of upto 10at.%. Grazing Incidence X-ray Diffraction results show wurtzite structure of the samples throughout the Ni concentration range while X-ray Near Edge Structure (XANES) and Extended X-ray Absorption Fine Structure results at Zn and Ni K edges show that Ni is substituting Zn in ZnO lattice and no other extra phase is present in the samples. The substitution of Zn by Ni is further confirmed by O K-edge XANES measurements. Photoluminescence measurements on the samples and theoretical simulations of the XANES spectra at Ni and O K-edges have been used to explain the room temperature ferromagnetic character on the basis of the presence of oxygen vacancies in the samples.