检索结果-南通市图书馆

Chinese Journal of Chemistry 2012年第9期30卷 2198-2204页

作者：严德荣黄海瑛何天白 State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Aead-emy of SciencesGraduate School of Chinese Academy of Sciences ChangchunJilin 130022China

We have investigated the crystallization and morphological behaviors of poly（ε-caprolactone）-b-poly（L-lactide）（PCL-b-PLLA） in its autophobic dewetted ultrathin films （-11 nm） using atomic force microscopy （AFM） and transmission electron microscopy （TEM）. The autophobic dewetting process creates a well defined film geometry containing an extremely thin wetting layer （-4.5 nm） with densely distributed micrometer droplets atop, which re- stricts the primary nucleation process to occurring only in the droplets. In addition to the normally encountered flat-on lamellae, the growth of edge-on lamellae in such a thin wetting layer has been observed on both of two crys- tallization paths. In thermal crystallization, flat-on lamellae are favored at small supercoolings while edge-on la- mellae appear at very large supercoolings both in the droplets and the wetting layer. For cold crystallization, the edge-on lamellae can form easily in the droplets and grow into the wetting layer even at very small supercoolings. These observations are explained on the basis that the nucleation and lamellar orientation are strongly affected by the film geometry, the crystallization paths, and the applied supercoolings.

关键词： crystallization autophobic dewetting poly(ε-caprolactone)-b-poly(L-lactide) ultrathin film

Magnetic anisotropy and magnetization reversal of ultrathin iron films with in-plane magnetization on Si（111） substrates

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2012年第7期21卷 5-10页

作者：刘郝亮何为杜海峰房亚鹏吴琼张向群杨海涛成昭华 State Key Laboratory of Magnetism and Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China

The magnetic anisotropy and magnetization reversal of single crystal Fe films with thickness of 45 monolayer （ML） grown on Si（111） have been investigated by ferromagnetic resonance （FMR） and vibrating sample magnetometer （VSM）. Owing to the significant modification of the energy surface in remanent state by slight misorientation from （111） plane and a uniaxial magnetic anisotropy, the azimuthal angular dependence of in-plane resonance field shows a six-fold symmetry with a weak uniaxial contribution, while the remanence of hysteresis loops displays a two-fold one. The competition between the first and second magnetoerystalline anisotropies may result in the switching of in-plane easy axis of the system. Combining the FMR and VSM measurements, the magnetization reversal mechanism has also been determined.

关键词： magnetic anisotropy magnetization reversal ultrathin film

Formations and morphological stabilities of ultrathin CoSi_2 films

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2012年第8期21卷 453-458页

作者：朱志炜高歆栋张志滨朴颖华胡成张卫吴东平 State Key Laboratory of ASIC and System School of MicroelectronicsFudan University Solid-State Electronics the Angstro¨m LaboratoryUppsala University

In this paper we investigate the formations and morphological stabilities of Co-silicide fihns using 1-8-nm thick Co layers sputter-deposited on silicon （100） substrates. These ultrathin Co-silicide films are formed via solid-state reaction of the deposited Co films with Si substrate at annealing temperatures from 450 ℃ to 850 ℃. For a Co layer with a thickness no larger than i nm, epitaxially aligned CoSi2 films readily grow on silicon （100） substrate and exhibit good morphological stabilities up to 600 ℃. For a Co layer thicker than 1 nm, polycrystalline CoSi and CoSi2 films are observed. The critical thickness below which epitaxially aligned CoSi2 film prevails is smaller than the reported critical thickness of the Ni layer for epitaxial alignment of NiSi2 on silicon （100） substrate. The larger lattice mismatch between the CoSi2 film and the silicon substrate is the root cause for the smaller critical thickness of the Co layer.

关键词： silicide epitaxial alignment ultrathin film

Advancing mid-infrared microdisk laser emission with Tm:YAG

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2024年第7期67卷 91-96页

作者： Zhaocong Wang Huiqi Li Lei Wang Yang Tan Feng Chen School of Physics State Key Laboratory of Crystal MaterialsShandong UniversityJinan 250100China

Mid-infrared microcavity lasers have important applications in biosensing,mid-infrared spectroscopy,and environmental ***,the low output power of existing mid-infrared microcavity lasers hinders their practical *** drawback is attributed to the insufficient laser gain medium,which limits the development of mid-infrared whispering-gallerymode(WGM)*** address this issue,we have employed ion implantation-enhanced etching to fabricate Tm:YAG thin films as effective gain media for mid-infrared WGM *** Tm:YAG thin film,with a thickness of 2μm,exhibits excellent fluorescence ***,the Tm:YAG thin film is processed using focused ion beam to form microdisks with a diameter of 30μ*** 785 nm laser pumping,the maximum output power of the Tm:YAG microdisk at 2023.1 nm is229μW,with a slope efficiency of 2.9%.This work demonstrates the outstanding potential of Tm:YAG as a mid-infrared laser gain medium,providing a new option for the development of mid-infrared lasers.

关键词： microdisk microlaser ultrathin film

同方期刊数据库

Low Temperature DC Sputtering Deposition on Indium-Tin Oxide film and Its Application to Inverted Top-emitting Organic Light-emitting Diodes

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2008年第2期24卷 179-182页

作者： Hui LIN Junsheng YU Shuangling LOU Jun WANG Yadong JIANG State Key Laboratory of Electronic Thin films and Integrated Devices School of Optoelectronic Information University of Electronic Science and Technology of China （UESTC） Chengdu 610054 China

Indium tin oxide （ITO） ultrathin films were prepared on glass substrate by DC （direct current） magnetron sputtering technique with the assistance of H2O vapor to avoid potential surface damage. The film properties were characterized by X-ray diffraction （XRD） technique, four-point probe method and spectrophotometer. The results show that the deposited ITO film with introduced H2O during sputtering process was almost amorphous. The average visible light transmission of 100 nm ITO film was around 85% and square resistivity was below 80 Ω/square. The film was used as the transparent anode to fabricate an inverted top-emitting organic light-emitting diodes （IT-OLEDs） with the structure of glass substrate/Alq3 （40 nm）/NPB （15 nm）/CuPc （x nm）/ITO anode （100 nm）, where the film thickness of CuPc was optimized. It was found that the luminance of this IT-OLEDs was improved from 25 cd/m^2 to more than 527 cd/m^2 by increasing the thickness of CuPc, and luminance efficiency of 0.24 lm/W at 100 cd/m^2 was obtained, which indicated that the optimized thickness of CuPc layer was around 15 nm.

关键词： Inverted top-emitting organic light-emitting diodes Indium-tin-oxide ultrathin film DC sputtering

Preparing ultrathin MgB2 Thin film by Ex-situ Annealing of Mg-B Precursor film

在线全文

学校读者我要写书评

暂无评论

Preparing Ultrathin MgB2 Thin Film by Ex-situ Annealing of M...

Fast Evaporation Enabled ultrathin Polymer Coatings on Nanoporous Substrates for Highly Permeable Membranes

中国材料大会2012

作者： Qian Dai Ruorun Ma Qingrong Feng Huai Zhang Qianqian Yang Ruijuan Nie Furen Wang School of Physics State Key Laboratory for Artificial Microstructures and Mesoscopic Physics Peking University

ISBN: (纸本)9783037856079

ultrathin MgB2 film is essential for the fabrication of MgB2 superconducting single photon detectors （SSPDs）. In this paper, we prepared 20nm and 10nm MgB2 film using ex-situ annealing of Mg-B multilayer method. The precursor films were prepared by electron beam evaporation. A flowing Mg vapour and H2 was introduced in the annealing process to keep MgB2 thin film thermodynamically stable. The annealing temperature was between 680℃ and 740℃ and annealing time was 1-10min. 20nm MgB2 films on MgO（111） substrates had the critical temperature （Tc） of 32.2K. The films grew along c-axes direction. As the substrate changed to SiC（001） and Al2O3（001）, T c decreased to 30.3K and 10.2K respectively. For 10nm MgB2 film on SiC（001） substrate, Tc was 24.2K. The self-field critical current density for 10nm and 20nm film on SiC（001） substrate was 2.1×10 6 A/cm 2 and 2.3×10 6 A/cm2 , respectively. AFM image showed that the film had a flat surface with mean roughness of 0.899nm for 10nm MgB2 film.

关键词： MgB2 Superconducting film ultrathin film

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

The Innovation 2021年第1期2卷 93-99页

作者： Xiansong Shi Lei Wang Nina Yan Zhaogen Wang Leiming Guo Martin Steinhart Yong Wang State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical EngineeringNanjing Tech UniversityNanjingJiangsu 211816P.R.China Institut fur Chemie neuer Materialien Universitat at OsnabruckBarbarastr.749069 OsnabruckGermany

Thin polymer coatings covering on porous substrates are a common composite structure required in numerous applications,including membrane separation,and there is a strong need to push the coating thicknesses down to the nanometer scale to maximize the ***,producing such ultrathin polymer coatings in a facile and efficient way remains a big ***,uniform ultrathin polymer covering films(UPCFs)are realized by a facile and general approach based on rapid solvent *** fast evaporating dilute polymer solutions spread on the surface of porous substrates,we obtain ultrathin coatings(down to30 nm)exclusively on the top surface of porous substrates,forming UPCFs with a block copolymer of polystyrene-blockpoly(2-vinyl pyridine)at room temperature or a homopolymer of poly(vinyl alcohol)(PVA)at elevated *** selective swelling of the block copolymer and crosslinking of PVA,we obtain highly permeable membranes delivering2–10 times higher permeance in ultrafiltration and pervaporation than state-of-the-art membranes with comparable *** have invented a very convenient but highly efficient process for the direct preparation of defective-free ultrathin coatings on porous substrates,which is extremely desired in different fields in addition to membrane separation.

关键词： fast evaporation ultrathin film block copolymer selective swelling membrane separation

Highly crystalline,highly stable n-type ultrathin crystalline films enabled by solution blending strategy toward organic single-crystal electronics

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第1期35卷 321-325页

作者： Yang Liu Shuyu Li Yihan Zhang Xiaoting Zhu Fangxu Yang Fei Jiao Wenping Hu Tianjin Key Laboratory of Molecular Optoelectronic Sciences Department of ChemistrySchool of ScienceTianjin UniversityTianjin 300072China Haihe Laboratory of Sustainable Chemical Transformations Tianjin 300192China

The development of n-type semiconductor is still far behind that of p-type semiconductor on account of the challenges in enhancing carrier mobility and environmental ***,by blending with the polymers,n-type ultrathin crystalline thin film was successfully prepared by the method of meniscus-guided ***,the n-type crystalline films exhibit ultrathin thickness as low as 5 nm and excellent mobility of 1.58 cm^(2) V^(-1) s^(-1),which is outstanding in currently reported organic n-type ***,the PS layer provides a high-quality interface with ultralow defect which has strong resistance to external interference with excellent long-term stability,paving the way for the application of n-type transistors in logic circuits.

关键词： n-type organic field effect transistors ultrathin film High-performance Composites

Preparation of large,ultra-flexible and free-standing nanomembranes of metal oxide-polymer composite and their gas permeation properties

在线全文

学校读者我要写书评

暂无评论

Clean Energy 2017年第1期1卷 80-89页

作者： Anteneh Mersha Roman Selyanchyn Shigenori Fujikawa Graduate School of Engineering Kyushu UniversityFukuoka 819-0395Japan WPI International Institute for Carbon-Neutral Energy Research(WPI-I2CNER) Kyushu UniversityFukuoka 819-0395Japan Center for Molecular Systems(CMS) Kyushu UniversityFukuoka 819-0395Japan Laboratory for Chemistry and Life Science Tokyo Institute of Technology4259 NagatsutachoMidori-kuYokohama226-8503Japan

In this work,fabrication of free-standing nanomembranes of metal oxide(MO_(x))and polymers by simple spin-coating method is ***,double-layer nanomembranes containing MO_(x) and epoxy resin of polyethyleneimine and poly[(o-cresyl glycidyl ether)-co-formaldehyde]were ***-standing nanomembranes were successfully prepared,but defects formed in the metal oxide nanolayer during sharp bending of the *** overcome fragility of MO_(x) nanolayer,poly(vinyl alcohol)nanolayers were introduced between MO_(x) nanolayers by layer-by-layer(LbL)assembly *** LbL nanomembrane was also free-standing and was highly flexible during macroscopic membrane *** after transfer of the LbL nanomembrane onto a porous support,it did not have apparent cracks,confirmed by scanning electron microscopy(SEM).The LbL nanomembrane sustained low gas permeance,confirming the absence of significant defects,although it shows excellent *** believe that the presented LbL nanomembrane could be a platform useful for the design of molecular nanochannels,which is the next challenge for efficient gas separation.

关键词： nanomembranes free-standing film ultrathin film layer-by-layer assembly metal oxide gas permeation