【摘要】 研究了极化条件对三方 /四方相共存 (即准同型相界 ,简称MPB)的铌锑锆钛酸铅 (PNSZT)压电陶瓷性能和结构的影响 .利用XRD探讨了三方、四方相共存PNSZT压电陶瓷极化过程中畴转向、相变、晶格常数的变化、应变 ,分析讨论了极化作用机理 .XRD结果分析表明 :两相共存压电陶瓷极化过程中畴转向的同时伴随着相变 (四方相→三方相 )、应变、晶格常数变化 ;随着极化程度的提高 ,试样的应变量和 90°畴转向率不断增加 ;当达到极化饱和状态时 ,它们也达到最大值 ,其中应变的最大值为 0 .4% ,90°畴的转向率最大值为 41.6 % ,此时样品的介电常数和机电耦合系数也达到最大值 .当 90°畴转向率高和应变大时 ,材料的机电耦合系数和介电常数也大 .90°畴转向率和应变是表征极化程度的微观结构物理量 .最优极化条件是得到最佳压电性能陶瓷的关键之一更多还原

【Abstract】 Influence of polarization conditions upon the properties and structures of lead niobium-stibium zirconate-titanate (PNSZT) piezoelectric ceramics, in which there are tetragonal and rhombohedral phases coexistent (morphotropic phase boundary, MPB), was studied. The domain_rotation, phase change, the change of lattice constant and strain in PNSZT ceramics during polarization process, were explored by means of XRD. The XRD results show that there are phase change (tetragonal phase to rhombohedral phase), strain and the change of lattice constant when domain_rotation of the sample occurrs in polarization. The strain and 90° domain_rotation rate of the sample increase steadily when increasing the extent of polarization. The strain and the rate of 90° domain_rotation reach the maximum values when polarization is in its saturation state. At the same time, the dielectric constant ( ε T 33 / ε 0) and electro_mechanical coupling factor ( K p) of the sample come to their maximum. The maximum strain is 0.4% and the maximum 90° domain_rotation rate is 41.6%. The electro_mechanical coupling factor and dielectric constant increase in accordance with the increase of the rate and strain of 90° domain_rotation. The rate and strain of 90° domain_rotation are microstructure physical parameters to characterize the level of polarization. The optimum polarization condition is one of the key factors to obtain the ceramics with the optimum piezoelectricity.更多还原