Microstructural and Ferroelectric Properties of Bi_0.5(Na,K)_0.5TiO₃-Based Modified by Bi_0.5Li_0.5TiO₃ Lead-Free Piezoelectric Ceramics

Abstract

Lead-free ceramics of composition (0.97 ¹ x)Bi 0.5 Na 0.4 K 0.1 TiO 3 -0.03BiAlO 3 -xBi 0.5 Li 0.5 TiO 3 (BNKTBA-xBLTO) were synthesized using solid state technique. The strong enhancements in ferroelectric and electric-field-induced strain were obtained. The electric-field-induced strain values were increased from 410 pm/V to 688 pm/V for 6 mol% BLTO-added which results from the phase transition from rhombohedral to tetragonal structure. The maximum spontaneous polarization increased from 26.5 µC/cm 2 to 30.8 µC/cm 2 for 4 mol% BLTO solid solution in BNKTBA and then decreased as BLTO was further added. We expect that this work could be helpful for further understanding the original enhancement in electrical field-induced strain in lead-free BNKT-based ceramics due to comparison between A-and B-site co-modifications.