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fesem在Bi系高温超导材料研究中的应用

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电子显微学报 2002年第5期21卷 733-734页

作者：孟均武庆兰刘庆韩征和清华大学应用超导中心北京100084 清华大学材料科学与工程系北京100084

利用热场发射扫描电镜（fesem）的基本功能，通过对比样品的简单分析，展示Bi系高温超导材料的微观特性。

关键词： fesem Bi系高温超导材料热场发射扫描电镜表面形貌微观分析

Structural,optical and antimicrobial properties of pure and Agdoped ZnO nanostructures

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Journal of Semiconductors 2022年第3期43卷 78-86页

作者： Sagar Vikal Yogendra K.Gautam Anit K.Ambedkar Durvesh Gautam Jyoti Singh Dharmendra Pratap Ashwani Kumar Sanjay Kumar Meenal Gupta Beer Pal Singh Smart Materials and Sensor Laboratory Department of PhysicsCh.Charan Singh UniversityMeerutUttar Pradesh 250004India Department of Genetics and Plant Breeding Ch.Charan Singh UniversityMeerutUttar Pradesh 250004India Nanoscience Laboratory Institute Instrumentation CentreIIT RoorkeeRoorkee 247667India Department of Physics University of RajasthanJaipur 302004India Department of Physics SBSRSharda UniversityGreater NoidaUttar PradeshIndia

In the present work,zinc oxide(ZnO)and silver(Ag)doped ZnO nanostructures are synthesized using a hydrothermal method.Structural quality of the products is attested using X-ray diffraction,which confirms the hexagonal wurtzite struc-ture of pure ZnO and Ag-doped ZnO nanostructures.XRD further confirms the crystallite orientation along the c-axis,(101)plane.The field emission scanning electron microscope study reveals the change in shape of the synthesized ZnO particles from hexagonal nanoparticles to needle-shaped nanostructures for 3 wt%Ag-doped ZnO.The optical band gaps and lattice strain of nanostructures is increased significantly with the increase of doping concentration of Ag in ZnO nanostructure.The anti-microbial activity of synthesized nanostructures has been evaluated against the gram-positive human pathogenic bacteria,Staphylococcus aureus via an agarose gel diffusion test.The maximum value of zone of inhibition(22 mm)is achieved for 3 wt%Ag-doped ZnO nanostructure and it clearly demonstrates the remarkable antibacterial activity.

关键词： zinc oxide silver hydrothermal fesem antimicrobial activity Staphylococcus

蓝猪耳花粉管细胞壁超微结构的fesem和AFM比较研究

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安徽农业科学 2011年第35期39卷 21802-21804页

作者：吴娟子江苏省农业科学院畜牧研究所江苏南京210014

[目的]比较场发射扫描电镜(fesem)和原子力显微镜(AFM)观察蓝猪耳花粉管表面形貌和细胞壁中纤维素微纤丝排列的效果。[方法]蓝猪耳花粉离体培养2 h后,利用fesem和AFM原位观察无损的花粉管表面形貌和细胞壁的精细结构。[结果]fesem可见... 详细信息

[目的]比较场发射扫描电镜(fesem)和原子力显微镜(AFM)观察蓝猪耳花粉管表面形貌和细胞壁中纤维素微纤丝排列的效果。[方法]蓝猪耳花粉离体培养2 h后,利用fesem和AFM原位观察无损的花粉管表面形貌和细胞壁的精细结构。[结果]fesem可见花粉管表面粗糙的网状结构;AFM可获得花粉管的三维立体图像,并可见花粉管细胞壁物质的精细结构和纤维素微纤丝的排列情况。[结论]AFM是一种观察花粉管表面结构和细胞壁中纤维素微纤丝排向的有效手段。

关键词：花粉管蓝猪耳纤维素微纤丝 AFM fesem

Band gap tuning and p to n-type transition in Mn-doped CuO nanostructured thin films

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Journal of Semiconductors 2022年第1期43卷 59-68页

作者： R.Rahaman M.Sharmin J.Podder Department of Physics Bangladesh University of Engineering and TechnologyDhaka 1000Bangladesh

Here we discuss the synthesis of copper(II)oxide(CuO)and manganese(Mn)-doped CuO thin films varying with 0 to 8 at%Mn using the spray pyrolysis technique.As-deposited film surfaces comprised of agglomerated spherical nanoparticles and a semi-spongy porous structure for 4 at%Mn doping.Energy dispersive analysis of X-rays confirmed the chemical composi-tion of the films.X-ray diffraction spectra showed a polycrystalline monoclinic structure with the predominance of the(11)peak.Optical band gap energy for direct and indirect transitions was estimated in the ranges from 2.67-2.90 eV and 0.11-1.73 eV,respectively.Refractive index and static dielectric constants were computed from the optical spectra.Electrical resistivity of CuO and Mn-doped CuO(Mn:CuO)thin films was found in the range from 10.5 to 28.6Ω·cm.The tiniest electron effective mass was calculated for 4 at%Mn:CuO thin films.P to n-type transition was observed for 4 at%Mn doping in CuO films.Carrier con-centration and mobility were found in the orders of 10^(17)cm^(-3)and 10^(-1)cm^(2)/(V·s),respectively.The Hall coefficient was found to be between 9.9 and 29.8 cm^(3)/C.The above results suggest the suitability of Mn:CuO thin films in optoelectronic applications.

关键词： Mn:CuO spray pyrolysis fesem XRD band gap Hall effect

Enhanced visible-light photocatalytic activity of samarium-doped zinc oxide nanostructures

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Journal of Rare Earths 2020年第1期38卷 29-38页

作者： Sukriti Prakash Chand Vishal Singh Department of Physics National Institute of TechnologyKurukshetra 136119India Centre for Materials Science&Engineering National Institute of TechnologyHamirpur 177005India

In the present work,we have synthesized samarium doped zinc oxide nanostructures(Zn1-xSmxO;x=0.00,0.02,0.04 and 0.06) via chemical precipitation method and studied their structural,morphological,optical and photocatalytic properties.X-ray diffraction(XRD) patterns,PL and Raman spectra results indicate that the undoped and Sm-doped ZnO nanostructures are crystallized in a hexagonal wurtzite structure.fesem images show that the morphology of the sample changes from cubical to hexagonal nanostructures with increase in Sm3+doping concentration.The EDX spectra confirm the incorporation of Sm3+ion in ZnO.The influence of Sm3+doping on the structure,morphology,absorption,emission and photocatalytic activity of ZnO nanostructures were investigated systematically.The addition of Sm3+ion leads to a red shift in the optical energy band gap from 3.19 to 2.67 eV and hence,increases the visible light absorption ability.The presence of E2(H) and E1(LO) modes in microRaman spectra confirms the crystallinity and defects in the samples.The detailed photocatalytic experiments reveal that Sm-doped ZnO nanostructures show the maximum photodegradation efficiency for Methylene blue(MB) dye for x=0.04,i,e.,94.94%,under visible light irradiation.The photocatalytic efficiency improves by 6.98 times when ZnO is doped with rare earth metal ion(Sm3+) and is a potential candidate for practical applications.The investigation demonstrates that as-synthesized nano-sized photocatalysts act as an efficient photocatalyst for the degradation of MB dye.

关键词： Photocatalysis Sm-doped ZnO fesem Micro-Raman UV-Visible spectroscopy Rare earths

Solution combustion synthesis of Fe-Ni-Y_2O_3 nanocomposites for magnetic application

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Journal of Central South University 2015年第1期22卷 23-29页

作者：刘烨秦明礼章林贾宝瑞陈鹏起张德志曲选辉 School of Materials Science and Engineering University of Science and Technology Beijing Aerospace Research Institute of Materials and Processing Technology

Fe-Ni-Y2O3 nanocomposites with uniform distribution of fine oxide particles in the gamma Fe Ni matrix were successfully fabricated via solution combustion followed by hydrogen reduction. The morphological characteristics and phase transformation of the combusted powder and the Fe-Ni-Y2O3 nanocomposites were characterized by XRD, fesem and TEM.Porous Fe-Ni-Y2O3 nanocomposites with crystallite size below 100 nm were obtained after reduction. The morphology, phases and magnetic property of Fe-Ni-Y2O3 nanocomposites reduced at different temperatures were investigated. The Fe-Ni-Y2O3 nanocomposite reduced at 900 °C has the maximum saturation magnetization and the minimum coercivity values of 167.41 A/(m2·kg)and 3.11 k A/m, respectively.

关键词：纳米复合材料应用磁性饱和磁化强度 fesem 纳米复合物均匀分布 Y2O3

Magnetic transitions and butterfly-shaped hysteresis of Sm-Fe-Al-based perovskite-type orthoferrite

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Journal of Rare Earths 2015年第9期33卷 965-971页

作者： M.A.Ahmed N.G.Imam M.K.Abdelmaksoud Y.A.Saeid Materials Science Lab. Physics Department Faculty of Science Cairo University Materials Science Lab. Experimental Physics Department Nuclear Research Center Atomic Energy Authority

A1 doped SmFeO3 （SmFel_xmlxO3; 0.0〈x〈0.15; step 0.05） were prepared by double sintering ceramic technique. The obtained samples were crystallized in single phase structure except the sample with x=0.15. The unit cell volume was found to decrease with increasing AI substitution in orthoferrite. The effective magnetic moment （μeff） and the Curie constant （C） were calculated from the reciprocal of the molar magnetic susceptibility （Z-1） versus absolute temperature plot and found to attain maximum value for the parent sample. The magnetic behavior showed two different magnetic transitions, viz, N6el temperature （TN） and spin reorientation （TsR） transitions. The M-H hysteresis loop of the parent sample took butterfly-shape as a result of different contributions anisotropies. From the magnetic properties measurements, it was obviously found that B-site cation dilution resulted in a drastic decrease in the magnetization. Surprisingly large value of the coercive field was obtained for the undoped sample;Hc=6198.80e. Based on the mentioned results, one can recommend the use of such orthoferrite in magnetic recording media and as pining layer in spin valve for spin- tronic applications.

关键词： SmFeO3 magnetization fesem crystal structure spintronics spin reorientation butterfly-shaped hysteresis anisotropy rare earths

Distinguished discriminatory separation of CO2 from its methane-containing gas mixture via PEBAX mixed matrix membrane

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Chinese Journal of Chemical Engineering 2018年第1期26卷 73-80页

作者： Pouria Abbasszadeh Gamali Abbass Kazemi Reza Zadmard Morteza Jalali Anjareghi Azadeh Rezakhani Reza Rahighi Mohammad Madani Nanotechnology Research Center Research Institute of Petroleum Industry(RIPI)P.O.Box:14665-1998TehranIran Chemical&Chemical Engineering Research Center of lran P.O.Box:14335-186TehranIran College of Environment Standard SquareP.O.Box:31746-118KarajIran Department of Research and Development Sharif Ultrahigh Nanotechnologists(SUN)CompanyP.O.Box:13488-96394TehranIron Nanotechnology Department Agricultural Biotechnology Research Institute of lran(ABRII)AREEO*** KarajIran

Highly selective separation of CO_2 from its methane-containing binary gas mixture can be achieved by using Poly(ether-block-amide)(PEBAX)mixed matrix membranes(MMMs).According to fesem and AFM analyses,silica-based nanoparticles were homogenously integrated within the polymer matrix,facilitating penetration of CO_2 through the membrane while acting as barrier for methane gas.The membrane containing 4.6 wt% fumed silica(FS)(PEBAX/4.6 wt%FS)exhibits astonishing selectivity results where binary gas mixture of CO_2/CH_4 was used as feed gas.As detected by gas chromatography,in the permeate side,data showed a significant increase of CO_2 permeance,while CH_4 transport through the mixed matrix membrane was not detectable.Moreover,PEBAX/4.6 wt%FS greatly exceeds the Robeson limit.According to data reported on CO_2/CH_4 gas pair separation in the literature,the results achieved in this work are beyond those data reported in the literature,particularly when PEBAX/4.6 wt%FS membrane was utilized.

关键词： CO2 分离能混合过膜煤气甲烷矩阵 fesem

Holmium Oxide Film as a Saturable Absorber for 2μm Q-Switched Fiber Laser

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Chinese Physics Letters 2017年第5期34卷 48-51页

作者： M.F.A.Rahman M.F.M.Rusdi M.Q.Lokman M.B.H.Mahyuddin A.A.Latiff A.H.A.Rosol K.Dimyati S.W.Harun Department of Electrical Engineering University of Malaya Kuala Lumpur 50603 Malaysia Photonics Research Centre University of Malaya Kuala Lumpur 50603 Malaysia Faculty of Electrical Engineering University Teknologi Mara Shah Alam 40450 Malaysia

This work reports on the use of the holmium oxide （Ho2O3） polymer film as a saturable absorber （SA） for generating stable Q-switching pulses operating in a 2μm region in a thulium-doped fiber laser cavity. The SA is prepared by diluting a commercial Ho3O2 powder and then mixing it with polyvinyI alcohol （PVA） solution to form a Ho2O3-PVA film. A tiny part of the film about 1mm×1 mm in size is sandwiched between two fiber ferrules with the help of index matching gel. When incorporated in a laser cavity driven by a 1552-nm pump, stable Q-switching pulses are observed at 1955nm within the pump power range of 363 491 roW. As the pmnp power increases within this range, the repetition rate rises from 26 kHz to 39 kHz, as the pulse width drops from 4.22μs to 2.57μs. The laser operates with a signal-to-noise ratio of 47dB, and the maximum output power and the pulse energy obtained are 2.67mW and 69ng, respectively. Our results successfully demonstrate that the Ho2O3 film can be used as a passive SA to generate a 2μm pulse laser.

关键词： m Q-Switched Fiber Laser SA fesem