B位等价掺杂SrBi4Ti4O15铁电材料的性能研究

采用了传统的固相烧结工艺，制备了不同Zr和Hf掺杂量的SrBi₄Ti_4-xZr_xO₁₅（x=000,003, 006,010,020）和SrBi₄Ti_4－xHf_xO₁₅（x=000,0005, 0015,0030,0060）的陶瓷 关键词： 4Ti_4-xZr_xO₁₅')" href="#">SrBi₄Ti_4-xZr_xO₁₅ 4Ti_4－xHf_xO₁₅')" href="#">SrBi₄Ti_4－xHf_xO₁₅ 铁电性能 介电性能

Effect of B-site equal-valent doping on ferroelectric properties of SrBi4Ti4O15 ceramics

The structures and properties of Zr and Hf-modified SrBi₄Ti₄O₁₅（SBTi） ceramics were investigated. We find that the basic crystal structure is not changed after the substitution of equal-valent cations Zr⁴⁺ and Hf⁴⁺ for the Ti⁴⁺ ions at B site in SBTi. Compared with the higher-valent cation doping （V, Nb）, Zr⁴⁺ and Hf ⁴⁺ substitution can also improve the ferroelectric property of SBTi. The enhancement of remnant polarization （2P_r） by Hf⁴⁺ doping is obviously larger than that by Zr⁴⁺ doping, though these two cations have almost the same radius. This indicates that the reduced concentration of oxygen vacancy is not the only reason responsible for the improvement of the 2P_r in the B site doping, and other uncertain reasons should also be considered. The piezoelectric properties of these ceramics are investigated briefly. The tendency of piezoelectric constant changing with the doping dosage is nearly consistent with the tendency of 2P_r. Meanwhile, the dielectric properties of these ceramics are investigated, the Curie temperature of the samples varieds slightly with the doping amount, which implies that the good thermal stability of SBTi is not sacrificed.