摘要
采用高温固相合成了一种新的类Sr2Be2B2O7族化合物KCaZn2(BO3)2F,利用粉末X射线衍射精修其晶体结构。该晶体同KCdZn2(BO3)2F同构,为三方晶系,空间群为P31c,单胞参数为a=5.03096(5),c=15.3940(2),Z=2。晶体基本阴离子基元是平面三角形的BO3和四面体的ZnO3F基元,两个基元通过共顶的O原子相连,在ab平面形成二维的十二元环的(Zn3B3O6F3)∞结构。(Zn3B3O6F3)∞结构通过F原子连接,形成(Zn6B6O12F3)∞双层单元,双层单元之内的两层BO3基元排列方式基本相反。(Zn6B6O12F3)∞双层单元与同它中心对称的另一个(Zn6B6O12F3)∞双层单元在c方向堆垛成三维的结构,K+和Ca2+分别位于(Zn6B6O12F3)∞双层单元的层内和层间空隙处。紫外可见漫反射光谱表明该晶体在400～2500 nm范围具有高的透过率,晶体的紫外截止波长为235 nm。
New Sr2Be2B2O7 family compound KCaZn2(BO3)2F was synthesized by solid-state reaction.The crystal structure was determined and refined from X-ray powder diffraction data.The title compound was isostructural to KCdZn2(BO3)2F and crystallized in trigonal space group P31c with cell parameters of a= 5.03096(5) ,c=15.3940(2) ,Z=2.The basic anions in the structure were planar BO3 and tetrahedral ZnO3F groups.Two groups were connected by sharing vertex O atoms to form infinite twelve-membered(Zn3B3O6F3)∞ layer at ab plane.The adjacent layers with twisted BO3 groups were linked with bridge F atoms to form(Zn6B6O12F3)∞ double layers.The double layers were stacked with the other centro-symmetric double layers in c direction into a three-dimensional framework.K+ were occupied within the channel(Zn6B6O12F3)∞ double layers and Ca2+ located in between two neighboring double layers,respectively.The heat analysis shows that title compound is non-congruent melt.And it has a wide transparent region from 400-2500 nm with a UV cut-off about 235 nm according to the UV-VIS diffuse reflectance spectra.
出处
《人工晶体学报》
EI
CAS
CSCD
北大核心
2013年第5期799-803,共5页
Journal of Synthetic Crystals
基金
国家自然科学基金(90922036
51032004/E0201)
山东大学晶体材料国家重点实验室开放课题(KF1110)资助
作者简介
夏明军（1982-），男，安徽省人，博士。
通讯作者：李如康，博士，研究员。E-mail：rkli@mail．ipc．ac．cn
