Ferroelectric Fatigue of KNN Ceramics

Effect of ZnO on (ferroelectric) fatigue retention and thermal stability of ferroelectric properties in lead free (K0.5Na0.5)(Nb0.7Ta0.3)O3 ceramics

“…In the case of KNN based ceramics, cation vacancies are generally formed due to the evaporation of potassium or sodium while high temperature sintering and in order to maintain the charge oxygen vacancies are created. The diffusion of oxygen vacancies present in KNNT due to volatilization of alkali metals 35,36 and their aggregation lead to domain wall pinning and consequently resulting in 5% fatigue (aer 10 9 cycles). The fatigue is overcome to a large extent in the case of KNNT2 because the Zn 2+ that enters KNNT matrix acts like a donor dopant and thus there is reduced oxygen vacancies concentration.…”

Structure and electrical properties of (0.965 − x)(K0.48Na0.52)NbO3–xBiGaO3–0.035(Bi0.5Na0.5)ZrO3 piezoelectric ceramics

“…8 Among them, potassiumsodium niobate (KNN) have attracted much attention owing to their excellent ferroelectric properties, high Curie temperature and better environmental compatibility, which has been widely recognized as one of the most promising candidates for leadfree piezoelectric ceramics. [13][14][15] The utilization of various preparation methods have been considered as one of useful approaches to improve properties of KNN based ceramics, such as spray pyrolysis, 16 spark-plasma sintering (SPS), 17 hydrothermal synthesis, 18,19 tape casting, 13 ultrasonic irradiation. [13][14][15] The utilization of various preparation methods have been considered as one of useful approaches to improve properties of KNN based ceramics, such as spray pyrolysis, 16 spark-plasma sintering (SPS), 17 hydrothermal synthesis, 18,19 tape casting, 13 ultrasonic irradiation.…”