Effects of Mn-doping on anti-fatigue and anti-leakage current characteristics in KNN single crystals

In this work, we illuminate the influences of Mn doping on the domain structure, ferroelectric properties, and piezoelectric properties of K0.4Na0.46NbO3 (KNN) lead-free single crystals. We simultaneously obtained a low leakage current and high anti-fatigue properties in Mn:KNN single crystals. The valence state of the Mn ion changes after annealing from trivalent to bivalent. The micro-domain structure images show that the domain structure of Mn-doped KNN single crystals is more complex with a smaller size. In addition, the occupying mechanism of Mn in KNN is discussed. Moreover, ion doping is of great significance to the further study of low leakage resistance and good anti-fatigue properties for KNN-based ferroelectric materials.