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在AO-B_2O-M_2O_5(A为碱土金属,B为碱金属,M为Nb、Ta)三元体系中发现存在一类通式为A_2BM_3O_(10)的层状化合物,采用固相反应法首次合成了系列新化合物Sr_2KNb_3O_(10)、Sr_2NaNb_3O_(10)、Sr_2KTa_3O_(10)、Ca_2KT_3O_(10);以K_2CO_3为主要助熔剂,首次制备了Sr_2KNb_3O(10)、Ca_2KNb_3O_(10)的单晶体。单晶X射线衍射和电子衍射分析表明,A_2BM_3O_(10)型化合物属正交晶系,晶体结构可以描述为以共顶方式连结的三层[MO_6]八面体类钙钛矿层[A_2M_3O_(10)~-与层间阳离子B′有规则地交替排列。该类化合物极有可能是一类潜在的新型铁电材料。探讨了AB_2M_3O_(10)型化合物的形成规律、结构相容性及类钙钛矿层的结构可调性。以Sr_2KNb_3O_(10)的三层类钙铁矿结构为基础,首次设计、合成了通式为K[Sr_2Na_(n-3)Nb_nO_(3n+1)(n≥3)的4、5、6层新型类钙铁矿结构化合物。首次发现层状结构A_2BM_3O_(10)型化合物具有插层现象。通过层间离子交换反应和有机分子插入(Intercalation)反应,设计与合成了三层钙钛矿结构为骨架的新化合物和有机-无机复合物,首次制备了新铌酸盐HAr_2Nb_3O_(10)、HSr_2Nb_3O_(10)·1.5H_2O和A_2BM_3O_(10)型正己胺柱铌酸盐。根据结晶化学规律,首次合成了一系列与K_6CrNb_(15)O_(10)类质同象的新
In the ternary system AO-B 2 O-M 2 O 5 (A is alkaline earth metal, B is alkali metal and M is Nb, Ta), a class of layered compounds with the general formula A_2BM_3O_ (10) has been found and synthesized by solid-state reaction for the first time The new compounds Sr2KNb_3O_ (10), Sr_2NaNb_3O_ (10), Sr_2KTa_3O_ (10) and Ca_2KT_3O_ (10) were synthesized. Single crystals of Sr_2KNb_3O (10) and Ca_2KNb_3O_ (10) were prepared with K_2CO_3 as the main flux. Single crystal X-ray diffraction and electron diffraction analysis show that the crystal structure of A_2BM_3O_ (10) is orthorhombic. The crystal structure of A_2BM_3O_ (10) can be described as [MO_2] octahedral [A_2M_3O_ (10) ~ - with the interlayer cation B ’regularly arranged alternately. This type of compound is most likely a potential new type of ferroelectric material. The forming rules, structural compatibility and structural tunability of AB2M_3O_ (10) -type compounds were discussed. Based on the three-layered calcium-iron structure of Sr_2KNb_3O_ (10), the first, fourth, fifth and sixth layers of K [Sr_2Na_ (n-3) Nb_nO_ (3n + 1) New type of calcium-iron structure compounds. For the first time, it was found that the layered structure A_2BM_3O_ (10) has intercalation phenomenon. Through the interlayer ion exchange reaction and the intercalation reaction, new three-layered perovskite framework compounds and organic-inorganic composites were designed and synthesized. The new niobate HAr_2Nb_3O_ (10), HSr_2Nb_3O_ (10) · 1.5H_2O and A_2BM_3O_ (10) n-hexylamine niobate. According to the laws of crystallization chemistry, a series of new compounds similar to K_6CrNb_ (15) O_ (10)