【摘要】 弛豫型铁电单晶Pb(Mg1 /3 Nb2 /3)O3_PbTiO3[PMNT]的电畴结构与铁电性能随组分变化 :由纯PMN至PMNT6 7/33晶体 ,晶体铁电性能由弛豫型铁电体向正常铁电体方向转变 ,电畴结构由微畴—不规则宏畴—规则宏畴演化 ,压电性能逐步增强 .电畴类型的转化也可由电场和温度诱导 .三方相PMNT晶体 (0 0 1)与 (111)切型晶片在极化后仍维持多畴态 ,它们在压电性能上的差异可从畴壁运动与两相共存方面获得解释 .尽管受晶体组分与结构起伏的影响 ,电畴分布的不均匀性在退火与极化前后始终存在 ,但晶体生长后期的退火处理与极化条件的改善对调节电畴结构、提高压电性能仍有一定效应 .更多还原

【Abstract】 Domain structures and ferroelectric properties are found varied with compositions of Pb(Mg 1/3 Nb 2/3 )O 3-PbTiO 3[PMNT] crystals. From pure PMN to PMNT 67/33 crystals, ferroelectric behavior changes from typical relaxor ferroelectrics to normal ones with the domain structures varying in the evolution process: microdomains?? $irregular macrodomains?? $regular macrodomains, and the piezoelectric properties becoming stronger. The transition in the domain types can be induced by electric field and temperature as well. As for (001) and (111) cuts in rhombohedral phases, multi_domain states are remained after poling, thus, the differences in piezoelectric properties for the two kinds of cuts can be interpreted by the movement of domain walls and phase coexisting. Due to the composition heterogeneity and structure fluctuation, the non_uniform distribution of domain structures exists all the time before and after poling, before and after annealing. Even though, the domain structures can be adjusted by adopting annealing methods and optimal poling condition, which is favorable for the enhancement of the piezoelectric properties of PMNT crystals.更多还原