Chengchao Jin

Large electrostrictive effect in ternary Bi0.5Na0.5TiO3-based solid solutions

In the present work, a ternary solid solution (0.935-x)Bi0.5Na0.5TiO3-0.065BaTiO3-xSrTiO3 (BNBST, BNBSTx) was designed and fabricated using the traditional solid state reaction method. A morphotropic phase boundary between the ferroelectric long-range-order and relaxor pseudocubic phases was determined around x of 0.22 for poled solid solutions. The further increase of SrTiO3 substitution turned the depolarization temperature Td to below ambient temperature and led to a sharp decrease in the remnant polarization Pr and quasi-static piezoelectric constant d33. A large electrostrictive coefficient Q of 0.026 m4 C−2 was obtained for BNBST0.30, which was entirely comparable to the well-known electrostrictive material Pb(Mg1/3Nb2/3)O3, recently reported Bi0.5Na0.5TiO3-BaTiO3-K0.5Na0.5NbO3, and Bi0.5Na0.5TiO3-BaTiO3-KNbO3. Under a moderate electric field of 4 kV/mm, the electrostrictive strain can reach as high as ∼0.11%. Furthermore, the electric-field-induced strain exhibited weak temperature-dependent behavi...

Large strain response in PZT-PZN-PAN lead-based ceramics

Solid solutions of 0.8Pb(Zr0.52Ti0.48)O3-(0.2-x)Pb(Zn1/3Nb2/3)O3-xPb(Al1/2Nb1/2)O3 (PZT-PZN-PAN, PZT-PZN-xPAN) with x from 0 to 0.1 were fabricated and the dielectric, ferroelectric, piezoelectric properties were investigated in detail. Results show the crystal structure changes from coexists of tetragonal and rhombohedral to single rhombohedral phase. At a critical composition of 0.02, a maximum quasi-static piezoelectric coefficient d33 (410 pC/N) was obtained. Furthermore, it is found that the increment of PAN content could lead to increase the strain of PZT-PZN-xPAN ceramics, and a large strain response of ~0.24% with normalized strain Smax/Emax as high as 767 pm/V was obtained for the PZT-PZN-0.1PAN under a low electric field of ~3 kV/mm, which makes it a promising material for solid-state actuator applications.