| Autor: |
Hanchen Hu, Mankang Zhu, Yudong Hou, Hui Yan |
| Předmět: |
|
| Zdroj: |
IEEE Transactions on Ultrasonics Ferroelectrics & Frequency Control; May2009, Vol. 56 Issue 5, p897-905, 9p, 3 Black and White Photographs, 3 Graphs |
| Abstrakt: |
74 (Bi1/2Na1/2) TiO3-20.8 (Bi1/2K1/2) TiO3- 5.2BaTiO3-x MnCO3 lead-free piezoelectric ceramics were synthesized by conventional solid oxide routine. The tetragonal 74(Bi1/2Na1/2)TiO3-20.8(Bi1/2K1/2)TiO3-5.2 BaTiO3 (BNKB) exhibits high depolarization temperature Td of 195°C; however, its properties are far from satisfactory for practical application and need to be improved. The experiments show that the addition of MnCO3 reduces the tetragonality c/a and increases the cell volume. In addition, it revealed that the suitable addition of MnCO3 promotes the sintering and increases the densities of BNKB ceramics. The addition of MnCO3 also enhances the relaxor behavior of BNKB ceramics due to the reconstruct of the disorder arrays. Due to the effect of the crystal lattice, grain growth, and relaxor behavior, the optimal electric properties were realized at MnCO3 addition x of 0.16: the dielectric permittivity ϵr = 1047, dielectric dissipation tanδ= 0.022, piezoelectric strain d33 = 140 pC/N, mechanical coupling kp = 0.18, mechanical quality Qm = 89 while the depolarization temperature Td stays relatively high at 175°C. The effect and mechanism of Mn doping on the electrical properties were discussed in detail. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
|
