Effects of Mn doping on dielectric and ferroelectric characteristics of lead-free (K, Na, Li)NbO3 thin films grown by chemical solution deposition

High-quality lead-free piezoelectric x Mn-doped (K 0.48 Na 0.52 ) 0.985 Li 0.015 NbO 3 films (KNLN; x  = 0, 0.01, 0.02, 0.03) were successfully deposited onto Pt(111)/Ti/SiO 2 /Si(100) substrates by sol–gel method. Effects of Mn substitution on the microstructure, dielectric properties, ferroelectric properties, and leakage current of the KNLN films were investigated in detail. Mn-doping can significantly improve the ferroelectric properties and decrease the leakage current of KNLN films. Optimal dielectric properties were obtained in films doped with 2 mol% Mn, whose dielectric constant and dielectric loss at 1 kHz were 875 and 0.030, respectively. In addition, well-saturated ferroelectric P - E hysteresis loop with large remanent polarization (2 P r ) and coercive field ( E c ) of 22.5 μC/cm 2 and 65 kV/cm were obtained in 2 mol% Mn-doped KNLN film at an applied electric field of 200 kV/cm.