Structural, optical and magnetic properties of aluminum doped MnZnO films deposited by dip coating

Al doped MnZnO films were synthesized by sol-gel dip coating method on glass substrates. Films were annealed between 250 and 550 °C in an air furnace. The X-ray diffraction analysis showed that the films are polycrystalline having the hexagonal structure and a preferred orientation along (100) for films annealed for 2 h between 250 and 450 °C. Further increase in annealing temperature shifted the preferred orientation to (002) direction. Optical characteristics in the UV-Visible region showed increase in transmission from 70 to 85% when increasing the wavelength from 300 to 900 mm. All films showed room temperature anisotropic ferromagnetism. The annealing temperature had a prominent effect on the magnetic properties of the films which in turn increased saturation magnetization. Al doped MnZnO films exhibited a dense homogenous microstructure with grain sizes less than 80 nm as evaluated by SEM micrographs.