Piezoelectric ceramics are used in several electronic applications as sensors, actuators, energy harvesters, etc. due to their ability to convert mechanical energy into electrical energy, and vice-versa. Nowadays, it is of great research interest not only to obtain lead-free ceramic materials with high piezoelectric properties, but also to enhance fatigue endurance for future engineering applications. In this regard, the research of new piezoelectric materials have shown that (K,Na)NbO3-based (KNN-based) ceramics have comparable electrical properties with currently commercial Pb(Ti,Zr)O₃ (PZT). It has been reported that KNN-based ceramic improve their piezoelectric properties when they are doped with BaZrO₃ or (Ba,Ca)ZrO₃. These dopants promote a phase coexistence at room temperature, which induce the reorientation of ferroelectric domains through the polarization process, increasing the piezoelectric properties. However, fatigue resistance study has not been extensively investigated for these kinds of complex compositions, which is important to understand the cations substitution effect.
 
Therefore, in this work the fatigue endurance of BaZrO₃ and (Ba,Ca)ZrO₃ doped KNN-based ceramics was investigated to determine the effect of the different dopants. The electrical fatigue tests were conducted using a TF Analyzer 2000 system (aixACCT) by applying an electric field close to the coercive field of the material for 107 cycles and observing the piezoelectric and ferroelectric properties degradation. This test gives us a first approach of main degradation mechanisms such as internal cracks, domains pinning, and development of a bias field for bulk materials due to the addition of BaZrO₃ or (Ba,Ca)ZrO₃.