Ferroelectric and dielectric study in 0.78Na0.5Bi0.5TiO3-0.2SrTiO3-0.02K0.5Na0.5NbO3 lead free ceramic

This study investigates the ferroelectric and dielectric behavior in lead-free 0.78Na0.5Bi0.5TiO3-0.2SrTiO30.02K0.5Na0.5NbO3 ceramic synthesized by solid-state reaction. Application of electric fields ( A . epsilon(T, f) and tan delta(T, f) curves in the range 25-600 degrees C speculate the emergence of a modulated structure i.e. relaxor phase. Such behavior may be correlated to the evolution of highly polarizable dipolar entities (polar nano regions) of different symmetries. The gradual crossover of these polar nano regions results in temperature and frequencyinsensitive dielectric permittivity (120-320 degrees C, and 1 to 106 Hz) with epsilon >3200 (+/- 15 % fluctuation) at 150 degrees C.

Automated summary

This study investigates the ferroelectric and dielectric behavior in lead-free ceramic, speculating the emergence of a relaxor phase due to the evolution of highly polarizable dipolar entities of different symmetries. The temperature and frequency-insensitive dielectric behavior observed in the ceramic may be correlated to the gradual crossover of polar nano regions.