Improvement of the electrical properties of textured BNKT-modified (K, Na)NbO3 lead-free ceramics in the broad operating temperature range

In this study, the improvement in the electrical properties of textured BNKT-modified (K, Na)NbO3 ceramics was extensively investigated across a broad, high operating temperature range. Herein, the two crucial issues of phase transitions and microstructure improvement of BNKT-modified (K, Na)NbO3 ceramics were discussed utilizing the crystal orientation technique. Additionally, we have verified the existence of phase transition temperatures for the R–O phase (TR–O), O–T phase (TO–T), and T–C phase (TC). This is based on the research on the temperature-dependent characteristics of the random and textured BNKT-modified (K, Na)NbO3 lead-free ceramics in the temperature range of −100 to 420 °C. The experimental results revealed a significant improvement in the electrical properties of ceramics, which was attributed to the strategy of shifting TR–O and TO–T phase transitions to near RT, forming R–O–T phase boundaries. Besides, the textured KNLNS-BNKT ceramic with 82