Cobalt doped tin oxide diluted magnetic transparent semiconducting thin films prepared by spray pyrolysis technique: structural, optical and magnetic properties

In this study, Sn1−xCoxO2 (x = 0.00, 0.02, 0.05, 0.10, and 0.20) thin films with different dopants were deposited by spray pyrolysis technique. Tin chloride and cobalt chloride were dissolved in ethanol and distillated water and next were deposited onto glass substrate at T = 480 °C. Rutile structure of SnO2 without extra peak was shown in XRD pattern. The lattice parameters and cell volume of the prepared films were calculated. Optical properties of the films evidenced that all films were transparent films and their transparency reduced from 90% to 60%. Field Emission Electron Microscopic (FESEM) system was used to measure the thickness and morphology of surface the films. The grain size and film thickness were found about 200 nm and 300 nm, respectively. The electrical properties studied Vander Pauw technique and low resistivity ( $$\:2.53\times\:{10}^{-4}$$ Ω. cm) and high concentration 1021 /cm3 were obtained. Furthermore, the results indicated that all the films presented ferromagnetism at room temperature and the lowest dopant had the maximum magnetic saturation. Finally, the room temperature ferromagnetism of the films was explained based on Ruderman–Kittel–Kasuya–Yosida (RKKY) mechanism.