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Thin films of Mn-Fe co-doped ZnO deposited onto borosilicate glass substrates by rf-magnetron sputtering in argon gas pressure. The as deposited thin films show hexagonal wurtizite structure, without any secondary phases of Mn or Fe in host ZnO within XRD limit. The crystallite (D) of the films decreases with increase in argon working gas pressure. The field emission scanning electron microscope (FE-SEM) images show dense microstructure with increases in average grain size as a function of argon gas pressure are about ∼12 – 44 nm. The elemental composition of the as deposited thin filmswere confirmed by EDS spectra. The room temperature M-H plots show clear signature of ferromagnetic behavior with increase working gas pressure, the magnetic moment (Ms) of as deposited thin films is about 32 to 47 emu/cc as a function of working gas pressure. The increase in ferromagnetism in Mn-Fe co-doped ZnO thin films is due to coupled magnetic moments of multi atoms of Mn/Fe in host ZnO matrix.

Thin films of Co doped ZnO thin films have been deposited on fused quartz substrates by radio-frequency magnetron sputtering in mixed gas environment of Ar+ N2 with increase in nitrogen gas content in sputtering chamber up to 100%. The as deposited show the hexagonal wurtzite structure of ZnO with (002) peak along c-axis, without any indication of secondary phase of Co or N2 in ZnO matrix. The surface morphology of the films show dense microstructure. With increase in nitrogen gas composition the films show decrease in average grain size for as deposited films. The room temperature transmittance spectra of as deposited films varies about ∼92-87% show decrease with increase in nitrogen in the films. The estimated direct band gap of the films varies in the range between 4.91 -3.75 eV. The band gap show decrease with increase in nitrogen component in the films is attributed that nitrogen acts as dopant in ZnO matrix along with Co in host ZnO matrix.