Ferroelectric and piezoelectric properties ofSrZrO3-modified Bi0.5Na0.5TiO3lead-free ceramics
(1. Engineering Research Center for Integrated Mechatronics Materials and Components,
Changwon National University, Gyeongnam 641-773, Korea;
2. Korea Electrotechnology Research Institute, Gyeongnam 641-773,Korea)
Changwon National University, Gyeongnam 641-773, Korea;
2. Korea Electrotechnology Research Institute, Gyeongnam 641-773,Korea)
Abstract: The lead-free SrZrO3-modified Bi0.5Na0.5TiO3 (BNT-SZ100x, with x=0-0.15) ceramics were fabricated by a conventional solid-state reaction method. The effects of SZ addition on BNT ceramics were investigated through X-ray diffraction (XRD), scanning electron microscopy (SEM), ferroelectric and electric field-induced strain characterizations. XRD analysis revealed a pure perovskite phase without any traces of secondary phases. Ferroelectric and bipolar field induced-strain curves indicated a disruption of ferroelectric order upon SZ addition into BNT ceramics. A maximum value of remnant polarization (32 μC/cm2) and piezoelectric constant (102 pC/N) was observed at 5% (mole fraction) of SZ. Maximum value of the electric field-induced strain (Smax=0.24%) corresponding to normalized strain (Smax/Emax= d*33= 340 pm/V) was obtained at BNT-SZ9.
Key words: lead-free ceramics; BNT; perovskite structure; field induced strain