Structural and electromechanical properties of lead-free Na0.5Bi0.5TiO3–BaZrO3 ceramics



The effect of BaZrO3 (BZ) addition on the crystal structure, ferroelectric, and piezoelectric properties of Na0.5Bi0.5TiO3 (NBT) ceramics synthesized by a conventional solid-state reaction method was systemically investigated. The X-ray diffraction profile reveals the formation of single-phase perovskite structure for all BZ modified NBT ceramics in composition range (x = 0–0.08). With the increase in BZ content, the maximum dielectric constant (Tm) and depolarization temperature (Td) peaks shift towards lower temperatures. At room temperature, the ferroelectric response increase with increase in BZ concentration. A maximum value of remanent polarization (Pr) 30 µC/cm2 was obtained at x = 0.04 and, however, with further increase in BZ content polarizations values decrease. The piezoelectric constant (d33) increased from 60 pC/N for pure NBT to 112 pC/N for x = 0.040. Furthermore, a significant enhancement in the normalized strain (math formula = Smax/Emax = 500 pm/V) was observed at x = 0.055 which can be attributed to ferroelectric and relaxor ferroelectric phase transformation.