【摘要】 着重介绍了用Ｂｒｉｄｇｍａｎ方法生长的（１－ｘ）Ｐｂ（Ｍｇ１／３Ｎｂ２／３）Ｏ３－ｘＰｂＴｉＯ３（ＰＭＮ－ＰＴ）固溶体单晶在介电、压电、热释电性能及相变方面的一些特点：①异常高的压电常数ｄ３３（高达３０００ｐＣ／Ｎ以上），耦合系数ｋｔ（在０．６以上），ｋ３３（达０.９０），高的介电常数（高达５０００甚至更高），低的Ｑｍ值（约６０），热释电系数也较高．②强烈的各向异性．③随着ＰＴ含量的增加，系统的弛豫行为逐渐减弱，在ｘ～０．３３时，材料在室温下成为正常铁电体，但ＰＥ－ＦＥ相变并非正常铁电相变，表现为在Ｔ＞Ｔｍ时；　～Ｔ关系不遵守居里－外斯定律，而是遵守Ｓｍｏｌｅｎｓｋｉｉ的关系．该相变也明显地与弥散相变不同．这种行为可用无规场的观点加以解释． 对ＰＭＮ－ＰＴ陶瓷，其压电性能与最好的软性ＰＺＴ相似，而　和ｋ３１略大．更多还原

【Abstract】 Some special features in dielectric, piezoelectric properties and phase transition behavior of (1 - x)Pb(Mg1/3Nb2/3)O3 - xPbTiO3 (PMN-PT) (x=0.24, 0.3, 0.33 and 0.35) single crystals grown by Bridgman method were outlined: 1) Extremely high piezoelectric constant d33 (up to 3000 PC/N) and coupling factors k33 and kt (up to 0.94 and 0.62 respectively), low mechanical factor of merit (Qm~60), large dielectric constant (~5000).2) Strong orientation dependence of piezoelectric properties. 3) with increasing PT content, the system becomes less relaxational, but at least upto x=0.35, the system still partly exhibites relaxor feature: for x=0.33 and 0.35. ~ T curves look sharp enough to show a normal ferroelectric like feature, however when T> Tm the ~ T relation does not obey Curie-Weiss law, but follows Smolenskii’s relation. The piezoelectric properties of PMN-PT ceramics are similar to PZT-5H, but with higher e and k31.更多还原