Chemical crystallography: From inception to maturity

The use of single crystal X-ray diffraction to determine the structure of a chemical compound has been historically classified as ‘Chemical Crystallography’. The methodologies, the accuracy in experiments coupled with the modern computer gadgets and advances in technology makes this branch of science an unequivocal provider of accurate and precise measurements of molecular dimensions. Structure determination by powder diffraction, crystal engineering, charge density analysis and studies on molecules in excited states are the recent add-ons.     

Fluorescence Properties of Eu^3＋：Y2SiO5 Single Crystal

Fluorescence properties of Eu^3 :Y2SiO5 have been investigated.Transitions between ^5D and ^7Fwere were studied with transmission spectra,fluorescence spectra,photoluminescence excitation(or absorption) spectra and site selective fluorescence spectra.The X-ray powder diffraction pattern of Eu^3 :Y2SiO5 shows that the crystal belong to monoclinic,and lattice‘s constants a,b,c and β arc obtaned by a simulation with the measured diffraction angles.     

金属-有机骨架K-MOF的合成及性质表征

以硝酸钾为中心金属离子,1,4-苯二甲酸（H2BDC）、1,3,5-苯三甲酸（H3BTC）及混合物（H2BDC+H3BTC）为有机配体,N,N-二甲基甲酰胺（DMF）为溶剂,采用溶剂热法合成三种K-MOF晶体。通过X射线粉末衍射(PXRD)、红外光谱(FT-IR)、扫描电镜（SEM）及热重(TG)等方法对样品进行表征,考察不同配体对K-MOF的影响。结果表明:K+与H2BDC配位得到的长条状晶体,与H3BTC配位得到粉末状晶体,H2BDC与H3BTC同时存在时,K+优先与H3BTC配位得到粉末状晶体。K-MOF具有良好的热稳定性,在350℃内能保持结构的热稳定性。     

Infrared Absorption Spectra of Serpentine Cat＇s Eye from Sichuan Province of China

Infrared （IR） absorption spectra and X-ray powder diffraction （XRD） patterrns of sexpenfine cat＇s eye from Sichuan Province have been investigated, and infrared absorption bands of the serpentine have been assigned in this paper. The results indicate that the bands near 3 600 - 3 700 cm^-1 belong to the stretching absorption band VOH, the bands in 948 - 1 100 cm^-1 axe assigned to the stretching vibraling band Usvo, and the bands at 600 570 and 440 cm^-1 respectively belong to the bending vibration band VOH, δMg-O and δSi-O. The serpentine cat＇ s eye includes two types： chrysotile and antigorite. Chrysotile has a sharp and intensive band at 3 688 cm^-1 and a weak band at 3 643 cm^-1 , while antigorite has only one intensive band in the region. At vibration band VSi-O, chrysotile and antigorite have a similar feature at 1 071 cm^-1, but the band at 980 cm^-1 in anfigorite has been split into two bands in chrysotile - a strong one at 1 027 cm^-1 and a weak one at 949 cm^-1. In addition, antigorite has a characteristic bending vibrating band δMg-O at 570 cm^-1. Based on the analysis of the feature of crystal structure, their IR differences axe well explained.     

荧光增白剂在无磷洗衣粉中效能讨论

以常用表面活性剂LAS、AEO—9和助剂结晶型层状硅酸钠、4A沸石、荧光增白剂VBL、31配成实验用无磷洗衣粉。通过粉体白度实验，去污实验和循环洗涤实验，考察了荣光增白剂在洗衣粉中的效能．实验结果表明：添加荧光增白剂使物体白度提高；去污力比值提高，荧光增白剂VBL、31在农洗衣粉中的最佳添加量其质量分数是0.15%。     

X-ray Crystallography of biological macromolecules

The three-dimensional structures of thousands of biological macromolecules have been determined by X-ray diffraction, since the first structures were reported about half a century ago. The structures revealed how critical the shapes and sizes of the molecules are to perform various biological processes in living creatures. In addition to providing atomic details of how the molecules function and interact with other molecules, the structures help in designing medicines. K Suguna is at the Molecular Biophysics Unit Indian Institute of Science Bangalore. Her research involves the determination of the crystal structures of macromolecules by the X-ray diffraction method. She is interested in the structures and functions of biological macromolecules.     

闪石族11-12种阳离子占位的X射线衍射估算

阐述了用X射线粉末图上特征峰强度对已知阳离子占位建立线性统计模型,估算未知样品各阳离子占位方法。实测数据证实这不仅在理论上可能,在实验上也是可行的。无论钙质闪石、碱性闪石,估算的精度均达到90%左右,可满足晶体化学研究之需,对闪石种属定名与成分分析定名对比,准确率达80%-85%,从而否定了“闪石族不能用X射线粉末法研究”的断言。     

溶胶-凝胶法制备纳米In2O3粉体

With InCl₃·4H₂O being used as raw materials, the precursor of nano-sized In₂O₃ powder was prepared by hydrolysis, peptization and gelation of InCl₃·4H₂O. After calcination, nano-sized In₂O₃ powder was obtained. The powder was characterized by thermo-gravimetric and differential thermal analysis (TG-DTA), X-ray diffractometry (XRD) and transmission electron microscopy (TEM), respectively. Calculation revealed that the mean crystalline size increased with increasing the calcination temperature, but crystal lattice distortion rate decreased with the increasing in the average crystalline size. This indicated that the smaller the particle size, the bigger the crystal lattice distortion, the worse the crystal growing. The activation energies for growth of nano-sized In₂O₃ were calculated to be 4.75 kJ·mol⁻¹ at the calcination temperature up to 500°C; and 66.40 kJ·mol⁻¹ at the calcination temperature over 600°C. TEM photos revealed that the addition of the chemical additive (OP-10) greatly influenced the morphology and size of In₂O₃ particles.     

电荷补偿ZnMoO4:Tb3+发光材料的制备和光谱性能研究（英文）

采用高温固相法制备了电荷补偿ZnMoO4:Tb3+发光材料样品。XRD分析表明,样品在800℃条件下能得到纯ZnMoO4相。光谱分析显示样品在377nm的波长激发下,有较强的543nm的绿光发射。对不同电荷补偿离子的样品进行了详细分析,结果表明掺入合适的电荷补偿离子能增强样品的绿光发射。     

Si基薄膜的X射线衍射表征研究

简述了X射线衍射(X-Ray Diffraction,XRD)的基本原理,计算了硅晶体的消光特性,从理论上研究了Si基薄膜XRD表征的特征.研究结果表明:由于薄膜的择优生长,Si基薄膜XRD谱与粉晶XRD谱存在差异;并可能观测到Si基片的二级衍射峰.研究结果在实际应用中对分析硅基薄膜的晶体结构具有重要意义.     

氧化锌气凝胶的晶体结构分析

运用XRD精修方法,对不同退火温度下制备的氧化锌气凝胶样品的晶体结构进行分析,精修的Rwp值在可信的范围内,分别为10.48%和6.93%。在不同温度下退火的样品晶体结构不一样,随着退火温度升高,晶胞体积变小,从三斜晶系变化到单斜晶系。     

Epitaxial growth of Ga x In1−x As film by RF sputtering and physical properties of the films

Single crystal Ga _x In_1−x As films have grown up on GaAs(100) substrate at 375°C and on InP(100) substrate at 390°C, respectively, by the method of rf-sputtering with using undoped GalnAs polycrystal as target. However, on Si(100) or Si(111) substrates at 260–390°C, even at 465°C, only polycrystalline films were obtained. In addition, the structure, composition, electrical characteristic and optical properties of the Ga _x In_1−x As films were investigated using X-ray diffraction (XRD), reflection of high energy electron diffraction (RHEED), energy dispersion analyzer of X-ray (EDAX), Hall measurements and spectroscopic ellipsometry.     

光源对TiO2纳米粉体催化效果的影响

以钛酸丁酯为前躯体,采用溶胶-凝胶法制备TiO2粉体,并通过TEM和XRD分析方法对其结构性能进行表征.检测结果表明:TiO2粉体由5-10nm的球形颗粒组成,晶型为锐钛矿型.通过在不同光源下催化降解水杨酸溶液,对其光催化活性及影响因素进行了分析.实验结果表明:紫外光下此TiO2纳米粉体的光催化活性较高.     

新型配合物[Cu（cyclen）（H_2O）]~（2＋）的密度泛函理论研究

[Cu（cyc len）（H2O）]2＋（cyc len=1,4,7,10-四氮杂环十二烷）是一种新型的大环配合物.在其实验所测晶体结构基础上,文章运用量子化学密度泛函理论中的B3LYP/6-31G（d）方法,对其结构参数进行优化和频率分析,结果表明优化结构为稳定结构,且与实验吻合良好.最后,对配合物的前沿分子轨道及自然电荷布居进行了分析.     

Preparation of AlN thin films for film bulk acoustic resonator application by radio frequency sputtering

Aluminum nitride （AlN） thin films with high c-axis orientation have been prepared on a glass substrate with an Al bottom electrode by radio frequency （RF） reactive magnetron sputtering. Based on the analysis of Berg＇s hysteresis model, the improved sputtering system is realized without a hysteresis effect. A new control method for rapidly depositing highly c-axis oriented AlN thin films is proposed. The N2 concentration could be controlled by observing the changes in cathode voltage, to realize the optimum processing condition where the target could be fixed stably in the transition region, and both stoichiometric film composition and a high deposition rate could be obtained. Under a 500 W RF power of a target with a 6 cm diameter, a substrate temperature of 450 ℃, a target-substrate distance of 60 mm and a N2 concentration of 25%, AlN thin film with preferential （002） orientation was deposited at 2.3 μm/h which is a much higher rate than previously achieved. Through X-ray diffraction （XRD） analysis, the full width at half maximum （FWHM） of AlN （002） was shown to be about 0.28°, which shows the good crystallinity and crystal orientation of AlN thin film. With other parameters held constant, any increase or decrease in N2 concentration results in an increase in the FWHM of AlN.     

电场诱导间规聚苯乙烯相转变研究

The crystal structure and morphology of syndiotactic polystryene(sPS)melt-crystallized in various electrostatic fields have been investigated by using wide angle X-ray diffraction(WAXD),differential scanning calorimeter(DSC) and scanning electron microscope(SEM).WAXD and DSC analyses show that SPS is gradually transformed from a phase to β phase with increase of electrostatic intensity.The SEM observations indicate that the morphology of sPS micro-crystals is strongly dependent on electrostatic intensity applied to the sample during solidification.The variation of the micro-crystals orientation from disordered lamellae to ordered lamellare have been observed with increase of electrostatic intensity.     

Fluorescence Properties of Eu~(3 ) :Y_2SiO_5 Single Crystal

1　Ｉｎｔｒｏｄｕｃｔｉｏｎ　Ｅｕ3 :Ｙ2 ＳｉＯ5ｃｒｙｓｔａｌｉｓｕｓｅｄａｓａｎｅｗｌｕｍｉｎｅｓｃｅｎｃｅｍａｔｅｒｉａｌ.Ｂｅｃａｕｓｅｔｈｅｎｕｃｌｅａｒｍｏｍｅｎｔｓｏｆｔｈｅｃｏｍ ｐｏｓｉｔｅｅｌｅｍｅｎｔｓａｒｅｓｍａｌｌｉｎｔｈｉｓｃｒｙｓｔａｌ,ｔｈｅｓｐｉｎ ｓｐｉｎｉｎｔｅｒａｃｔｉｏｎｂｅｔｗｅｅｎｇｕｅｓｔａｎｄｈｏｓｔｉｏｎｓｉｓｍｉｎｉｍｉｚｅｄ .Ｔｈｅｇｕｅｓｔ ｈｏｓｔｉｎｔｅｒａｃｔｉｏｎｄｏｅｓｎｏｔｃａｕｓｅｌａｒｇｅａｄｄｉ ｔｉｏｎａｌｌｉｎｅｂｒｏａｄｅ…     

UHV／CVD生长SiGe／Si材料分析及应用研究

以Si2H6和GeH4为生长气源,采用UHV／CVD系统在Si（100）衬底上生长了Sil—xGex合金和Sil—xGex／Si多量子阱结构。采用X射线双晶衍射仪、扫描电子显微镜和原子力显微镜等仪器设备对样品的组份、界面和表面形貌等晶体质量进行了研究。SiGe合金中Si和Ge摩尔分数的比值随着Si2H6和GeH4流量比的增加按比例线性增加,比例因子为2．57。生长的Si0．88Ge0．12合金样品的界面清晰,表面平整,平均粗糙度仅为0．4nm,位错密度低于104／cm2。六周期Si0．88Ge0．12／Si多量子阱的X射线双晶衍射摇摆曲线中存在多级卫星峰和Pendellosung条纹。这些结果表明SiGe合金和SiGe／Si多量子阱均具有很好的晶体质量。     

Catalytic properties of CuO/Sn0.9Ti0.1O2 and CuO/Sn0.7Ti0.3O2 in NO＋CO reaction

Using SnxTi1-xO2 as carriers, CuO/Sn0.9Ti0.1O2 and CuO/Sn0.7Ti0.3O2 catalysts with different loading amounts of copper oxide (CuO) were prepared by an impregnation method. The catalytic properties of CuO/Sn0.9Ti0.1O2 and CuO/Sn0.7Ti0.3O2 were examined using a microreactor-gas chromatography (GC) NO CO reaction system and the methods of BET (Brun- auer-Emmett-Teller), TG-DTA (themogravimetric and differential thermal analysis), X-ray diffraction (XRD) and H2-temperature programmed reduction (TPR). The results showed that NO conversions of Sn0.9Ti0.1O2 and Sn0.7Ti0.3O2 were 47.2% and 43.6% respectively, which increased to 95.3% and 90.9% at 6 wt% CuO loading. However, further increase in CuO loading caused a decrease in the catalytic activity. The nitrogen adsorption-desorption isotherm and pore-size distribution curve of Sn0.9Ti0.1O2 and Sn0.7Ti0.3O2 represented type IV of the BDDT (Brunauer, Deming, Deming and Teller) system and a typical mesoporous sample. There were two CuO diffraction peaks (2θ 35.5° and 38.7°), and the diffraction peak areas increased with increasing CuO loading. TPR analysis also detected three peaks (α, β and γ) from the CuO-loaded catalysts, suggesting that the α peak was the reduction of the highly dispersed copper oxide, the β peak was the reduction of the isolated copper oxide, and the γ peak was the reduction of crystal phase copper oxide. In addition, a fourth peak (δ) of the catalysts meant that the SnxTi1-xO2 mixed oxides could be reductive.     

飞秒激光诱导硼酸盐基团的转变

1　Ｉｎｔｒｏｄｕｃｔｉｏｎ　Ｓｉｎｃｅｔｈｅ 90’ｓ ,ｔｈｅｆｅｍｔｏｓｅｃｏｎｄｌａｓｅｒｔｅｃｈｎｉｑｕｅｓｈａｖｅｂｅｅｎｕｓｅｄｔｏｓｔｕｄｙｖａｒｉｏｕｓｕｌｔｒａ ｐｒｏｃｅｓｓｗｉｔｈｉｎｍａｔｅｒｉａｌｓ,ｂｅｃａｕｓｅｏｆｉｔｓｈｉｇｈｔｉｍｅ ｒｅｓｏｌｕｔｉｏｎ .Ｉｎｃｈｅｍｉｃａｌｒｅａｃｔｉｏｎｓ ,ｃｈｅｍｉｃａｌｂｏｎｄｂｒｅａｋｉｎｇｏｒｂｏｎｄｆｏｒｍａｔｉｏｎｉｓｏｎｔｈｅｓｃａｌｅｏｆｆｅｍｔｏｓｅｃｏｎｄ (10 - 15ｓｅｃ ｏｎｄ) [1] .Ｗｉｔｈｆｅｍｔｏｓｅｃｏｎ…