Influence of Mn2+ on the electrical properties of textured KNN thick films

Textured K0.5Na0.5NbO3 thick film was prepared by the reactive templated grain growth method. The effects of Mn2+ doping on the phase structure, microstructure and electrical properties of the K0.5Na0.5NbO3 textured thick film were investigated. The grain orientation degree decreased with increasing Mn2+ and reduced to 50% for the thick film with 5 mol% Mn2+. The addition of Mn2+ improved the microstructure of the thick film. The electric properties of the thick film were also enhanced because of the high densification, the vacancy compensation effect and the acceptor doping effects of Mn2+. The K0.5Na0.5NbO3 thick film with 2 mol% Mn2+ doping possessed the optimum properties: Pr = 3.05 μC/cm2, Ec = 4.79 kV/cm, J = 4.6 × 10−6A/cm2 (at 25 kV/cm) and d33*=124 pm/V.