Synthesis and Crystal Structure of LiY(CN2)2, Having a Structure Related to That of NiAs

The new ternary carbodiimide LiY(CN₂)₂ was synthesized by solid state metathesis reaction between YF₃ and Li₂(CN₂) in a silica tube at 550 °C. The X‐ray single‐crystal structure determination yielded an orthorhombic crystal system (Pbcn, Z = 4, a = 982.0(3), b = 698.5(2), c = 613.4(2) pm). The crystal structure can be considered related to the NiAs structure. The carbodiimide ions are arranged in layers following the motif of a hexagonal closest packing of sticks. Lithium and yttrium cations occupy all octahedral voids in an ordered fashion, alternating on top of each other along the hcp stacking direction.     

RIG型磁光薄膜的研究进展及应用

随着光通信技术与光子集成电路的发展,非互易性器件作为光通信系统中重要的组成部分得到了越来越广泛的研究与应用。基于磁光效应制成的磁光隔离器和环行器是目前应用最为广泛的非互易性器件,为了将非互易性器件整块集成在硅片上,需制备性能与块状磁光材料相当的磁光薄膜。在近红外通信波段(1 550 nm),以钇铁石榴石(Y₃Fe₅O₁₂,YIG)为代表的稀土铁石榴石(RIG)具备优良的磁光效应,是最具应用前景的磁光材料之一。研究发现,使用稀土离子对YIG薄膜进行掺杂可以有效改善其磁光性能,尤其是Bi³⁺和Ce³⁺掺杂的YIG表现出巨法拉第效应。本文首先介绍了法拉第效应原理,介绍了三种常见磁光薄膜的生长方法,回顾了近年来的主要研究成果,介绍了磁光薄膜在光隔离器和环行器中的应用,最后对磁光薄膜的未来发展趋势进行了展望。     

Fluorescence properties of novel rare earth complexes using carboxyl-containing polyaryletherketones as macromolecular ligands

The fluorescence properties of a series of rare earth (Re³⁺ = Eu³⁺, Tb³⁺) polymeric complexes (PEK-Re³⁺-HLs) using three high-T_g novel carboxyl-containing polyaryletherketones (PEK) as macromolecular ligands and small molecules (HL) such as 1,10-phenanthroline (Phen), dibenzoylmethane (DBM) and 8-hydroxyquinoline (HQ) as co-ligands were investigated by means of fluorescence excitation and emission spectroscopy as well as fluorescence lifetime measurement methods. Among them, PEK-1-Re³⁺-Phens, in which the Re³⁺ ions were coordinated simultaneously with Phen and PEK-1 containing both carboxyl and bulky isopropyl groups on the polymer backbone, exhibited strong fluorescence intensities, long lifetimes, and good film-formation properties. The smooth films of PEK-1-Eu³⁺-Phen and PEK-1-Tb³⁺-Phen, cast from their DMF solutions, could emit bright red and green light under the UV lamp of 365 nm, respectively, which characteristics are of great significance for their potential applications in the large area display material fields. The excellent fluorescence properties of complexes in this study were attributed to the synergistic effects of PEK-1 ligand and Phen co-ligand. Especially, the rigid twisted structure and the bulky isopropyl substituents on PEK-1 backbone forced the coordinated rare earth ion moieties apart, and thus the probability of non-radiative decay rate of Re³⁺ ions at the excited levels were decreased to a large extent.     

Sol-Gel法制备La~(3+)改性的TiO_2纳米粉体

在常用的半导体光催化材料中,研究较多的有TiO2、ZnO、CdS等[1-3],其中TiO2因性能稳定、催化活性高、无毒、不产生二次污染和成本低廉等优点,在光催化降解污染物领域显示出优越的应用前景[3-6].     

Rare earth‐doped calcium‐based magnetic catalysts for transesterification of glycerol to glycerol carbonate

Several rare earth‐doped, calcium‐based magnetic catalysts were prepared for the synthesis of glycerol carbonate. The basicity and basic strength analysis of the catalysts showed that the doping of rare earth improved the basicity of the catalysts, and the doping of lanthanum maximized it. In addition, with the doping of lanthanum, the particle size of the catalyst became smaller to promote the organic reactants near the active sites of catalysts, thereby effectively improving the performance. NiFe₂O₄@[CaO‐La₂O₃] shows better catalytic performance with 99.0% yield of glycerol carbonate compared to the other catalysts. The NiFe₂O₄@(CaO‐La₂O₃) could be reused in six cycles without significant loss in activity.     

稀土元素的X射线荧光光谱分析

近十年来,国内外的稀土元素X射线荧光光谱分析工作有了很大进展。随着稀土应用的日益广泛,XRF不仅是常量稀土分析手段,也已用于微量和痕量稀土分析。本文着重在样品的预富集,制样技术,仪器条件,校正谱线干扰以及消除基体效应的数学校正法等方面做了阐述。     

高纯氧化镨样品ICP摄谱分析时光谱干扰校正方法的研究

本文提出了Pr_6O_(11)样品ICP摄谱分析时干扰系数法校正光谱干扰的方法和相应的计算机软件系统。建立了Pr基体对14种稀土杂质元素24条灵敏分析线的干扰系数表(KCT),利用所提出的方法分析了Pr_6O_(11)合成样品,由91个实验点所得回收结果可知,回收率在90～110%之间的占93.4%。可见校正是相当有效和十分必要的。     

二（2,4,4—三甲基戊基）膦酸稀土配合物的振动光谱

测定了二（２，４，４－三甲基戊基）膦酸（ＢＴＭＰＰＡ）及其稀土配合物Ｌｎ（ＢＴＭＰＰ）３在４０００～５０ｃｍ＾－１光谱区内的ＦＴ－ＩＲ光谱和部分配合物的激光拉曼光谱，对其谱带进行了经验归属。发现稀土氧键具有较高的离子键特性。由Ｌｎ－Ｏ伸缩振动频率值算出其近似力常数约８ｍ ｄｙｎ／ｎｍ。