  The structural, optical and magnetic properties of the Zn1-xMnxO (0 < x <
0.05) thin films synthesized by sol-gel technique have been analyzed in the
light of modification of the electronic structure and disorder developed in the
samples due to Mn doping. The films are of single phase in nature and no
formation of any secondary phase has been detected from structural analysis.
Absence of magnetic impurity phase in these films confirmed from morphological
study also. Increasing tendency of lattice parameters and unit cell volume has
been observed with increasing Mn doping concentration. The incorporation of
Mn2+ ions introduces disorder in the system. That also leads to slight
degradation in crystalline quality of the films with increasing doping. The
grain size reduces with increase in Mn doping proportion. The band gaps shows
red shift with doping and the width of localized states shows an increasing
tendency with doping concentration. It is due to the formation of impurity band
and trapping of Mn atoms, which leads to the generation of the defect states
within the forbidden band. Photoluminescence (PL) spectra shows gradual
decrease of intensity of exitonic and defect related peaks with increasing Mn
doping. Defect mediated intrinsic ferromagnetism has been observed even at room
temperaturenfor 5at% Mn doped ZnO film. The strong presence of
antiferromagnetic (AFM) interaction reduces the observed ferromagnetic moments.
