Electrical and band-gap properties of amorphous zinc-indium-tin oxide thin films

Zinc-indium-tin oxide (ZITO) films were grown by pulsed-laser deposition.Three different material compositions were investigated:ZITO-30,ZITO-50 and ZITO-70 in which 30％,50％ and 70％,respectively,of the...     

Preparation of quantum size of tin oxide: Structural and physical characterization

SnO_2 NPs were successfully prepared via a hydrothermal method. X-ray diffraction analysis con fi rmed the rutile tetragonal structure of SnO_2 NPs. The crystallite size increased from 1.18 to 5.06 nm with increasing the preparation temperature from 100 to 180 °C. The SEM photography of the products exhibited the agglomeration of the SnO_2 nanocrystals to large view particles, while TEM images con fi rmed the polycrystalline phase and crystallite size those analyzed from XRD. The UV–vis absorption of ethanol suspended SnO_2 NPs was measured. The optical band-gap energies(Eg) were signi fi cantly blue-shifted due to quantum con fi nement. Fluorescence spectra came to con fi rm this shift, where a clear shift in the maximum emission peak was observed. Stokes shift of SnO_2 nanocrystals was found to be crystallite size dependent.     

磁性氧化铁纳米线的制备与表征

通过溶胶-凝胶法在氧化铝模板（AAO）中制备出了磁性Fe_2O_3纳米线阵列,然后去除AAO模板得到磁性Fe_2O_3纳米线。用SEM,TEM,FTIR,EDX,VSM对磁性纳米线的形貌、微结构和磁性能进行表征。SEM和TEM结果显示磁性纳米线的直径约为50～80nm,长度在8～10μm,长径比为120～180;FTIR和EDX结果表明制备的产物是磁性Fe_2O_3纳米线;VSM结果表明磁性氧化铁纳米线阵列存在明显的磁各向异性。此外,采用Zeta电位仪对磁性Fe_2O_3纳米线表面的电性进行了研究,结果表明纳米线表面带正电荷,有利于和动物细胞相结合。     

Facile immobilization of heparin on bioabsorbable iron via mussel adhesive protein (MAPs)

Motivated by adhesive proteins in mussels, strategies using dopamine to modified surface have become particularly attractive. In the present work, we developed a novel and convenient method to modify the biodegradable Fe plates with heparin. Iron was first treated by a facile one-step p H-induced polymerization of dopamine, and then a high density heparin was successfully grafted onto the surface via coupling with polydopamine(PDA) active layer. Heparin immobilization contributed much longer blood clotting coagulation time than the pure Fe sample, and hence reduced the risk of thrombosis. Cell viability tests suggested that the heparin modified Fe plates were more favorable to the proliferation of ECV304 cells. In summary, the heparin modified Fe plates with good anti-thrombus properties and inhibiting the proliferation of VSMC cells provide great prospects for biodegradable iron.     

WSe2纳米颗粒的制备及表征

采用固相反应法用W粉和Se粉为原料,高能球磨压片后,在Ar气氛中反应合成WSe2纳米颗粒。研究结果表明,当退火温度高于400℃时,样品为WSe2的六方晶相。考察了反应温度、球磨时间、气流量大小和保温时间对合成反应的影响,并发现保温时间的加长并没给结晶带来有益的影响,而延长球磨时间能明显降低颗粒尺寸。     

电化学沉积CaWO4薄膜及表征

在室温条件下，采用恒电流电化学沉积技术直接在钨片基体上制备了白钨矿结构的CaWCId晶态薄膜。电化学反应的工艺参数为：电流密度为1mA／cm^2、电解液的pH值为13．0、电化学处理时间为1．5h。采用XP,D、XPS、SEM技术分析了制备的CAWO4薄膜的晶相、化学组成和表面形貌，所制备的薄膜是表面均匀致密的四方晶系的单相薄膜。     

Preparation and characterization of cobalt-doped iron pyrite(FeS_2) thin films

Iron pyrite (FeS_2) incorporated with cobalt dopant varying from 2%to 6%atomic ratio,was synthesized by using an aqueous hydrothermal process.The thin films of Co-doped FeS_2were fabricated by a vacuum thermal evaporation of synthesized FeS_2powder.The structural,electrical and optical properties of as-deposited and sulfurized films were investigated.The X-ray diffraction results indicated that the synthesized powder and thin films showed a cubic pyrite structure.The crystallinity of FeS_2was slightly degraded by the doping of cobalt.The dependence of thin-film resistance on the temperature indicated an increase of activation energy until 3 at%cobalt doping and then decreased the resistance with the increase of cobalt concentration.Hall effect measurements showed that the Co-doped samples have n-type conduction except for the 2 at%.The carrier concentration was in the order of 10~(18)cm~(-3),whereas,the carrier mobility decreased from 6.52 cm~2/V.s to 4.3 cm~2/V.s with the increase of cobalt dopant.The photosensitivity of undoped and cobalt-doped FeS_2films was measured under AM 1.5G and NIR light.The sulfurized films showed a higher photoresponse than the asdeposited films for both visible and IR lights.     

Crystal and electronic structure study of Mn doped wurtzite ZnO nanoparticles

The change in the crystal and electronic structure properties of wurtzite ZnO nanoparticles was studied according to Mn doping in the powder samples. The investigations were conducted by X-ray Absorption Fine Structure Spectroscopy (XAFS) technique for the samples prepared with different heating and doping processes. Electronic analysis was carried out by the collected data from the X-ray Absorption Near-Edge Structure Spectroscopy (XANES) measurements. Additional crystal structure properties were studied by Extended-XAFS (EXAFS) analysis. Longer heating periods for the undoped wurtzite ZnO samples were determined to own stable crystal geometries. However, for some doped samples, the distortions in the crystal were observed as a result of the low doping amounts of Mn which was treated as an impurity. Besides, the changes in oxygen locations were determined to create defects and distortions in the samples.     

锰系铁合金中锰与铁的联合测定

根据锰系铁合金中锰与铁的传统化学分析方法,通过理论分析和实验研究,简要论述了锰和铁联合测定的可行性和合理性     

六方中孔硅分子筛的合成与表征

以十二胺(DDA)为模板剂,采用溶胶凝胶法室温下合成了六方中孔硅分子筛原粉(HMS-DDA),分析了焙烧法与有机溶剂抽提法,特别是溶剂、抽提时间等因素对合成六方中孔硅分子筛(HMS)中孔结构的影响,利用XRD、FT-IR、HRTEM、XPS及TG-DTA等分析手段对其进行了表征。结果表明:焙烧温度、抽提溶剂及抽提时间对HMS-DDA的脱模及HMS材料的晶格重组、结构有序度及骨架稳定性有显著影响,其中以丙酮为溶剂抽提样品9 h,材料具有良好的中孔有序度和最稳定的中孔结构。同时证实了在HMS-DDA合成过程中,荷电为零的无机硅物种(I°)与中性伯胺分子(S°)之间依靠非静电力协同完成S°I°分子自组装。     

聚丙烯腈纤维表面“花”形纳米钯的合成与表征

将腈纶纤维进行部分偕胺肟化改性,与Pd(Ⅱ)进行反应,生成Pd(Ⅱ)-配合物纤维(Pd(Ⅱ)/AOFs),再经水合肼溶液还原,成功地在聚丙烯腈纤维表面生长出金属Pd微粒,SEM显示金属Pd纳米粒子堆积呈"菜花"型,均匀分布于纤维表面.典型的"钯花"直径大约在300nm,不同过程形貌显示了钯花的生长过程.IR显示Pd与纤维之间以化学键结合,XRD图谱在40.1°、46.6°、68.1°出现Pd特征衍射峰.     

电化学原子层沉积研究现状及沉积体系的构建

近年来,电化学原子层沉积(Electrochemical atomic layer deposition,E-ALD)技术在制备催化、光电及热电等功能薄膜的研究和应用方面取得了较大进展.概述了E-ALD的发展历史、沉积原理、研究及应用情况,介绍了课题组研发的E-ALD系统的构成和生长过程的控制机理.     

邻菲啰啉体系测量Fe（Ⅲ）的双峰单波长分光光度法研究

本文采用双峰单波长分光光度法测定Ｆｅ（Ⅲ），具有较高的灵敏度（ε＝５．５４×１０４Ｌ·ｍｏｌ（－１）·ｃｍ（－１）），常见离子干扰少，重现性好。对固体饮料和辽河水中Ｆｅ（Ⅲ）进行测定，回收率分别在９７．３—１０４．０％和９７．７—１０２．０％。     

不同还原剂制备氧化亚铜及其电化学性能研究

基于绿色化学的思想,运用软模板法成功的实现了环境友好型的不同还原剂如葡萄糖、麦芽糖等在水中还原Cu2+,制得了形貌不同的纳米氧化亚铜(Cu2O)晶体,用X射线衍射仪(XRD)和原子力显微镜(AFM)对所得产物进行表征,并研究了纳米Cu2O修饰电极的电化学行为。该制备方法简单易行,为纳米Cu2O的绿色合成提供了新的途径。     

Sr/Fe掺杂LaMnO3纳米微波吸收材料的制备与表征

用溶胶-凝胶法制备A位掺Sr,B位掺Fe的纳米级LaMnO3微波吸收材料粉体,用XRD和SEM表征该材料样品的晶体结构、颗粒形貌与尺寸,测量样品的微波吸收特性和电阻率。结果表明,于800℃煅烧的样品晶体结构为钙钛矿型;颗粒形貌为棒状,长度约100 nm,直径约20 nm;电导率在半导体的电导率范围内;当样品厚度为2 mm左右、Fe含量为0.12和0.14,Sr含量为0.2时,在2~18 GHz范围内,10 dB以上吸收带宽达6.2 GHz,最大吸收峰达34 dB;样品厚度为2.21 mm时,8 dB以上吸收带宽达8.5 GHz。     

对——甲砜苯丝氨酸合铜(II)纳米晶的合成及表征

通过室温固液反应及机械球磨法合成对——甲砜苯丝氨酸合铜 ( II)纳米晶 ,并通过元素分析 ,红外光谱及 X射线粉末及 TEM电子透镜对其性质进行了表征。研究表明 ,该纳米晶的平均粒径 72 nm,其组成为 ( CH3 SO2 C6H4 CHOHCHNH2 COO) 2 Cu。该纳米晶属正交晶系 ,晶胞参数 a=0 .3 894 nm,b=0 .3 91 2 nm,c=0 .3 890 nm,为一新型纳米材料     

对——甲砜苯丝氨酸合铜(II)纳米晶的合成及表征

通过室温固液反应及机械球磨法合成对——甲砜苯丝氨酸合铜 ( II)纳米晶 ,并通过元素分析 ,红外光谱及 X射线粉末及 TEM电子透镜对其性质进行了表征。研究表明 ,该纳米晶的平均粒径 72 nm,其组成为 ( CH3 SO2 C6H4 CHOHCHNH2 COO) 2 Cu。该纳米晶属正交晶系 ,晶胞参数 a=0 .3 894 nm,b=0 .3 91 2 nm,c=0 .3 890 nm,为一新型纳米材料     

工业纯铁表面自纳米化及其表征

利用高能喷丸(High energy shot peening,HESP)法在工业纯铁的表面获得一定厚度的纳米晶层,实现工业纯铁表面自纳米化。通过金相显微镜观测、扫描电子显微镜分析、显微硬度测试以及X线衍射计算分析,对工业纯铁表面自纳米化层的组织结构和性能进行研究分析。研究结果表明:采用HESP方法实现工业纯铁表面纳米化的主要工艺参数是:喷丸弹丸为直径1 mm的铸铁,喷丸压力为0.6 MPa,喷枪距离试样表面为5 cm,所获得的纳米晶的厚度随着喷丸时间的增加而增加;剧烈变形层由于晶粒得到了细化,其显微硬度大大提高,在距喷丸面10μm处,其显微硬度(HV)达到296.6,随着距喷丸面距离的增加,剧烈变形层的硬度不断减小;只要喷丸1 min,即可在工业纯铁表面获得平均晶粒粒径为68.4 nm、微观畸变为0.050%的纳米晶层;随着喷丸时间的延长,晶粒粒径越来越小,而微观应变越来越大;喷丸14 min可在工业纯铁表面获得平均晶粒粒径为28.5 nm、微观畸变为0.175%的纳米晶层。     

土壤氧化铁的活化与环境意义

综述了土壤氧化铁的形态和土壤氧化铁活化的主要途径:渍水条件下氧化铁的还原、有机质活化、氧化铁表面羟基化和质子化及耕作方式和细菌等的作用.因活化后的氧化铁具有巨大的比表面积和很强的表面化学活性,能吸附众多的重金属(如镉、铜、锌、铅)、非金属(如氟、硒)和含氧阴离子(如磷酸盐),对于控制土壤中环境污染物的迁移和转化是十分有意义的.     

纳米氧化铁的制备方法及进展

纳米氧化铁的制备方法有氧化沉淀法、水热法、强迫水解法、凝胶—溶胶法、胶体化学法、水溶胶萃取法等.通过分析比较各种纳米氧化铁的制备方法,提出了纳米氧化铁制备应向低成本、粒径可控、粒子均匀的方向发展.