A role of BNLT compound addition on structure and properties of PZT ceramics

In this research, effects of lead-free bismuth sodium lanthanum titanate (BNLT) addition on structure and properties of lead zirconate titanate (PZT) ceramics were investigated. PZT ceramics with addition of 0.1–3.0 wt%BNLT were fabricated by a solid-state mixed oxide method and sintering at 1050–1200 °C for 2 h to obtain dense ceramics with at least 96% of theoretical density. X-ray diffraction indicated that complete solid solution occurred for all compositions. Phase identification showed both tetragonal and rhombohedral perovskite structure of PZT with no BNLT phase detected. Scanning electron micrographs of fractured PZT/BNLT ceramics showed equiaxed grain shape with both transgranular and intergranular fracture modes. Addition of BNLT was also found to reduce densification and effectively limited grain growth of PZT ceramic. Optimum Hv and KIC values were found to be 4.85 GPa and 1.56 MPa.m1/2 for PZT/0.5 wt%BNLT sample. Among PZT/BNLT samples, room temperature dielectric constant seemed to be improved with increasing BNLT content. The maximum piezoelectric coefficient values were observed in pure PZT ceramic and were slightly decreased in BNLT-added samples. Small reduction of remanent polarization and coercive field in hysteresis loops was observed in BNLT-added samples, indicating a slightly suppressed ferroelectric interaction in this material system.

PZT/xBNLT (where x = 0.1–3.0 wt%) were fabricated by a solid-state mixed oxide and sintering methods. X-ray diffraction indicated that complete solid solution occurred for all compositions. Optimum Hv and KIC values were found for PZT/0.5 wt%BNLT sample. Among PZT/BNLT samples, room temperature εr seemed to be improved with increasing BNLT content. The maximum d33 values were observed in pure PZT and were slightly decreased in BNLT-added samples. Small reduction of Pr and Ec in hysteresis loops was observed in BNLT-added samples, indicating a slightly suppressed ferroelectric interaction in this material system.Figure optionsDownload as PowerPoint slide