深紫外磷酸盐及硼酸盐光学晶体材料的合成、结构及性能研究

发布时间：2018-06-28 16:29

本文选题：深紫外光学晶体 + 非线性　；参考：《山西师范大学》2017年硕士论文

【摘要】：深紫外光学晶体材料的合成一直是许多科研人员关注的热点。由于目前有商用价值的晶体比较少,而这一类型材料在医学、军事等领域又有着非常重要的应用。因而在本课题的研究中,我们通过高温固相反应,在磷酸盐和硼铍酸盐这两大体系中引入碱金属和碱土金属混合型阳离子,合成了四例新化合物,并对它们的结构和性能进行了研究。结果如下:1、利用Cs-Mg-P-O反应体系以及在此体系中引入d10组态的Zn~(~(2+)),先后合成了两种新的磷酸盐晶体,Cs_6Mg_6(PO_3)18(CMP)和Cs_2Mg Zn2(P_2O_7)_2(CMZP),并合成了它们的多晶粉末。CMP属于单斜晶系,结晶于非中心对称和极性P21空间群,晶胞参数为a=7.7437(4)?,b=34.1273(17)?,c=10.1063(5)?,β=90.414(2)?,V=2670.7(2)?3,Z=2。该化合物存在两条独立的一维[PO3]∞螺旋链,并与孤立的Mg O6八面体通过共享氧原子形成了一个新的三维阴离子骨架。非线性测试显示CMP在紫外区的粉末倍频效应约为KH_2PO_4(KDP)的0.1倍,并且能实现第I类相位匹配,其弱的极性响应被非线性系数的计算进一步确认。进一步的偶极矩计算表明,弱的倍频效应主要来源于畸变的Cs On多面体。CMZP属于单斜晶系,中心对称P21/c空间群,晶胞参数为a=13.5270(14)?,b=7.4464(8)?,c=14.6905(15)?,β=90.746(4)?,V=1479.6(3)?3,Z=4。该化合物的结构中含有一个新的[Mg Zn_2P_4O_20]14-结构单元,这个结构单元是由两个孤立的P_2O_7二聚体,两个无序的Mg/Zn O_4和一个Zn O_4四面体组成。这两个化合物的紫外-可见漫反射测试表明紫外截止边都低于190nm,能带理论计算表明这主要归因于O和P原子以及Zn原子之间的电子跃迁。2、在Li_2O-B_2O_3-BeO这个体系中合成了Li_(13)Be7B_9O_(27)和Li_(13)Mg Be_6B_9O_(27)晶体,都结晶于六方晶系P63/m空间群,有相同的分子式Li_(13)ABe_6B_9O_(27)(A=Be,Mg)。Li_(13)Be_7B_9O_(27)的晶胞参数为a=7.72789(19)?,c=18.8399(6)?,V=974.38(4)?3,Z=2;Li_(13)Mg Be_6B_9O_(27)的晶胞参数为a=7.731?,c=18.888?,V=977.8?3,Z=2。这两个化合物结构中都含有新的[Be_6B_9O_(33)]∞双层阴离子骨架,Li+和A~(2+)填充在阴离子骨架的空隙平衡电荷,不同的是它们的结构属于镜面对称的关系。需要特别指出的是,这两个化合物含有罕见的AO_6三棱柱的配位环境(A=Be,Mg),尤其是前所未有的Be O_6三棱柱结构,拥有超长的Be-O键长(2.2373(7)?),这改变了传统上Be-O基团只有强的共价键而没有完全离子键的认识。光学测试显示它们的紫外截止边都低于190 nm,能带理论计算解释它们的光学性质主要是由B-O和Be-O基团之间的电子跃迁决定的。热稳定性分析说明它们拥有优良的热稳定性。这表明这两种硼铍酸盐在深紫外都有潜在的应用价值。
[Abstract]:The synthesis of deep ultraviolet optical crystal materials has always been a hot spot for many researchers. Because of the low commercial value of crystal, this kind of material has very important applications in the fields of medicine and military. Therefore, in this study, we use the high temperature solid state reaction, in phosphate and beryllium salt, two In the large system, four new compounds were synthesized by the introduction of alkali metal and alkaline earth metal mixed cations, and their structure and properties were studied. The results are as follows: 1, two new phosphate crystals, Cs_6Mg_6 (PO_3) 18 (CMP) and Cs_2M, were synthesized by the Cs-Mg-P-O reaction system and the Zn~ (~ (2+)) introduced into the system in this system. G Zn2 (P_2O_7) _2 (CMZP), and synthesized their polycrystalline powder.CMP belongs to the monoclinic system, crystallized in the non centrally symmetric and polar P21 space group, the cell parameters are a=7.7437 (4)? B=34.1273 (17)?, c=10.1063 (5)?, beta =90.414 (2)?, V=2670.7 (2)? 3. There are two independent one-dimensional spiral chains with two isolated eight sides. A new three-dimensional anion skeleton is formed through the shared oxygen atom. The nonlinear test shows that the powder doubling effect of CMP in the ultraviolet region is about 0.1 times that of KH_2PO_4 (KDP), and can achieve phase I phase matching. The weak polarity response is further recognized by the calculation of nonlinear coefficients. Further dipole moment calculation shows that the weak frequency doubling efficiency is shown. The distortion based Cs On polyhedron.CMZP belongs to the monoclinic system, the centrally symmetric P21/c space group, the cell parameters of a=13.5270 (14)?, b=7.4464 (8)?, c=14.6905 (15)?, beta =90.746 (4)?, V=1479.6 (3)? 3. The compound contains a new [Mg Zn_2P_4O_20]14- structural unit, and this structural unit is composed of two isolated instances. _7 two polymer, two disordered Mg/Zn O_4 and a Zn O_4 tetrahedron. The UV visible diffuse reflectance tests of the two compounds show that the ultraviolet cut-off edges are lower than 190nm, and the theoretical calculation shows that this is mainly attributed to the electron transition.2 between the O and P atoms and the Zn atoms, and the Li_ (13) is synthesized in the Li_2O-B_2O_3-BeO system. O_ (27) and Li_ (13) Mg Be_6B_9O_ (27) crystals are crystallized in the P63/m space group of six square crystal systems, with the same molecular Li_ (13) ABe_6B_9O_ (27) (A=Be, Mg).Li_ (13) Be_7B_9O_ (27) cell parameters for a=7.72789 (6)? 6? 974.38 (4)? 3 The compound structure contains a new [Be_6B_9O_ (33)] (33)] double layer anion skeleton, Li+ and A~ (2+) fill the gap equilibrium charge of the anion skeleton, and their structure is mirror symmetry. It is special to point out that these two compounds contain a rare AO_6 three prism coordination environment (A=Be, Mg), especially in the former. The unknown Be O_6 three prism structure has a long Be-O bond length (2.2373 (7)?), which changes the understanding that the traditional Be-O group has a strong covalent bond without a complete ionic bond. Optical tests show that their UV cut-off edges are lower than 190 nm, and theoretical calculations explain that their optical properties are mainly from the electricity between the B-O and Be-O groups. Zi Yueqian decided. The thermal stability analysis shows that they have excellent thermal stability. This indicates that these two kinds of borylate have potential application in deep ultraviolet.
【学位授予单位】：山西师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O734

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