Lead-free piezoelectric thin films of Mn-doped NaNbO3–BaTiO3 fabricated by chemical solution deposition

Lead-free piezoelectric thin films of NaNbO3–BaTiO3 were fabricated on Pt/TiOx/SiO2/Si substrates by chemical solution deposition. Perovskite NaNbO3–BaTiO3 single-phase thin films with improved leakage-current and ferroelectric properties were prepared at 650 °C by doping with a small amount of Mn. The 1.0 and 3.0 mol% Mn-doped 0.95NaNbO3–0.05BaTiO3 thin films showed slim ferroelectric P–E hysteresis and field-induced strain loops at room temperature. The 1.0 and 3.0 mol% Mn-doped 0.95NaNbO3–0.05BaTiO3 films showed remanent polarization values of 6.3 and 6.2 μC/cm2, and coercive field of 41 and 55 kV/cm, respectively. From the slope of the field-induced strain loop, the effective piezoelectric coefficient (d33) was found to be 40–60 pm/V.