Structures and electrical properties of Mn- and Co-doped lead-free ferroelectric K0.5Na0.5NbO3 films prepared by a chemical solution deposition method

The un-doped, 2 mol% Mn- and 2 mol% Co-doped K0.5Na0.5NbO3 (KNN) films were prepared by a chemical solution deposition method. The crystalline phase and surface morphologies of KNN films hardly changed after Mn- and Co-doping. X-ray photoelectron spectrocopy analysis indicates that the introduction of both Mn and Co promoted the formation of KNN perovskite structure, and the most Mn2 + and Co2 + ions were oxidized into high-valence ions during thermal process. As a result, the leakage current density of the KNN films was decreased and the electrical properties were enhanced after the doping.