Structural and electromechanical properties of lead‐free Na 0.5 Bi 0.5 TiO 3 –BaZrO 3 ceramics

The effect of BaZrO 3 (BZ) addition on the crystal structure, ferroelectric, and piezoelectric properties of Na 0.5 Bi 0.5 TiO 3 (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 ( T m ) and depolarization temperature ( T d ) peaks shift towards lower temperatures. At room temperature, the ferroelectric response increase with increase in BZ concentration. A maximum value of remanent polarization ( P r ) 30 µC/cm 2 was obtained at x  = 0.04 and, however, with further increase in BZ content polarizations values decrease. The piezoelectric constant ( d 33 ) increased from 60 pC/N for pure NBT to 112 pC/N for x  = 0.040. Furthermore, a significant enhancement in the normalized strain ( d 33 *  =  S max / E max  = 500 pm/V) was observed at x  = 0.055 which can be attributed to ferroelectric and relaxor ferroelectric phase transformation.