Pb(Mg_(1/3)Nb_(2/3)O_3-PbTiO_3晶体组分对结构与性能的影响  

Composition dependence of the structures and electrical properties of Pb(Mg_(1/3)Nb_(2/3)O_3-PbTiO_3 single crystals

作　　者：许桂生[1] 王晓锋[1] 杨丹凤[1] 段子青[1] 

机构地区：[1]中国科学院上海硅酸盐研究所人工晶体中心

出　　处：《材料研究学报》2005年第5期506-511,共6页Chinese Journal of Materials Research

基　　金：国家自然科学基金50072038资助项目~~

摘　　要：用熔体Modified Bridgman法生长出尺寸直径40 mm长度80 mm的弛豫铁电单晶PMNT90/10,表明该方法不仅适合在准同型相界(MPB)附近生长PMNT单晶,也适合生长PT含量很低的PMNT单晶.在生长出的PMNT90/10晶体中,铁电相与顺电相两相共存,并呈现亚微畴结构特征.随着晶体组分由PMN组元变化到MPB组分附近,PMNT的电畴结构呈现微畴-亚微畴- 不规则宏畴-规则宏畴演化系列,而介电弛豫特性则逐步弱化.PMNT固熔体的电学性能依赖于晶体组分,(001)切型PMSNT90/10晶体的压电常数d33约80 pC/N,显著低于MPB附近组分,但其介电常数ε达到12600,明显高于后者.The relaxor-based ferroelectric single crystal 0.90Pb（Mg1/3Nb2/3）O3-0.10PbTiO3 （PMNT90/10） with the size of 40 mm in diameter and 80 mm in length was grown by a modified Bridgman technique. This suggests that the technique is suitable for the growth of PMNT crystals with lower PT content as well as those near the morphotropic phase boundary （MPB）. PMNT90/10 crystal had the structure of a ferroelectric phase coexisting with a paraelectric one. A peculiar submicrodomain was found within the ferroelectric phase-predominated regions. With the changing of the compositions from PMN to PMNT near MPB, the ferroelectric domains evolve in the order of microdomain-sub-microdomain-irregular macrodomain-regular macrodomain, and the relaxor behavior becomes weak gradually. Moreover, PMNT90/10 crystal on the （001） cut exhibits lower values of piezoelectric constant d33 （80 pC/N） and higher values of dielectric constant ε （12, 6000） than the crystals near MPB.

关 键 词：无机非金属材料 晶体生长 BRIDGMAN法 Pb(Mg1/3Nb2/3)O3-PbTiO3 弛豫铁电体 压电性能 

分 类 号：TB321[一般工业技术—材料科学与工程]