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铅基复合钙钛矿型弛豫铁电单晶体PMNT,PZNT的生长基元为多种[BO_6]配位八面体.这些同型生长基元受本身稳定性的制约而在熔体中存在的几率不同.相对于[MgO_6]~(10-),[ZnO_6]~(10-)八面体基元来说,[NbO_6]~(7-),[TiO_6]~(8-)是更为有利的八面体基元.在基元组装过程中,各种[BO_6]八面体基元在稳定性、尺寸大小与电价上的分异致使生长界面对基元有一定的选择性,从而造成了晶体生长时成分与结构的短程起伏,并为有序畴及其它化学缺陷团簇的形成提供了条件.当加入掺质PbTiO_3时,由于[TiO_6]~(8-)与[NbO_6]~(7-)两种基元在组装时的类聚性及[TiO_6]~(8-)对晶体稳定性的贡献,晶体的微区成分与结构得以调制,焦绿石相得以抑制,这构成了用Bridgman法能直接从熔体中生长出纯钙钛矿相PMNT单晶的基础.而[MgO_6]~(10-)与[ZnO_6]~(10-)八面体基元的差异致使PMNT,PZNT两单晶的生长难度有别,这在选择合适的生长方法时需加以考虑.
Lead-based perovskite relaxor ferroelectric single crystal PMNT, PZNT growth of a variety of basic elements [BO_6] coordination octahedron.These growth units by their own stability constraints exist in the melt with different probability . [NbO_6] ~ (7 -), [TiO_6] ~ (8-) are more favorable for the [MgO_6] ~ (10 -) and [ZnO_6] ~ (10-) In the process of assembly of primitives, the differentiation of various [BO_6] octahedral motifs in stability, size and electricity causes the growth interface to have a certain selectivity to the primitives, resulting in crystal growth The composition and structure of the short-range fluctuations, and for the orderly domains and other chemical defects cluster formation provided.When doping PbTiO_3, due to [TiO_6] ~ (8-) and [NbO_6] ~ (7-) two The clustering of seed elements at assembly and the contribution of [TiO 6] ~ (8-) to the crystal stability, the composition and structure of the micro-domains of the crystal are modulated and the pyrochlore phase is suppressed, which constitutes a straight- The growth of pure perovskite PMNT single crystals was found in the melt, while the difference of [MgO 6] 10- and [ZnO 6] -10 (10-) octahedrons caused the growth difficulty of PMNT and PZNT single crystals Different, this is the right choice To be considered when growth method.