Characterization of ‘Al’ co-doped Zn1-xMnxO Films Deposited by Spray Pyrolysis

Zn1-xMnxO is one of the prominent materials that have attractive fundamental properties suitable for device applications that include spintronics. In the present study, aluminium co-doped Zn1-xMnxO films have been synthesized by chemical spray pyrolysis on Corning 7059 glass substrates at a constant temperature of 400 oC. The ‘Al’ composition in the layers was varied in the range, 0.0-0.07 and ‘Mn’ composition in the layers was fixed at x = 0.15. The compositional analysis shows the presence of zinc, manganese, oxygen and aluminium without any other impurities. All the films were polycrystalline and showed the hexagonal wurtzite structure of ZnO with (002) crystal plane as the preferred orientation. The film exhibited a maximum optical transmittance of > 60% and the evaluated band gap was 3.22 eV at an Al-doping level of 0.07. The highest remnant magnetization of 3.14x10-4 emu and coercive field of 464.8 Oe was observed in this study for an Al-doping of 0.07. The crystallite size, morphology, optical band gap and electrical resistivity were found to be significantly affected by changing the ‘Al’ concentration.