Influence of Al percentage on the magnetic, optical, and structural properties of Al-doped CoZnO thin films

Al-doped CoZnO thin films were deposited by sol-gel dip coating technique with 1–3% of Al at a constant withdrawal speed of 250 mm/s and their characteristics were studied. With increase in the Al percentage in the CoZnO thin films, there was no structural change identified. X-ray diffraction of the Al-doped CoZnO thin films assured the generation of the hexagonal wurtzite structure. The optical and structural stuff of the thin films was tailored with increase in Al contents which were confirmed by X-ray diffraction. Crystallite size was increased from 25.7 to 29.2 nm with increase in Al %. Band gap was decreased from 3.23 to 3.20 eV by an increase in the Al dopant percentage from 1 to 2%, but for 2.5–3% of Al doping, it increased to 3.88 eV. This increase in the band gap for higher Al percentage was due to the Brustein-Moss effect. Dip-coated films possessed polycrystalline grains with web-like and wire-like morphology. The room temperature ferromagnetic behavior of Al-doped CoZnO thin films is also confirmed which increased with increase in Al percentage.