共查询到20条相似文献,搜索用时 31 毫秒
1.
P.A. Mosier-Boss L.P.G. ForsleyP. Carbonnelle M.S. MoreyJ.R. Tinsley J.P. HurleyF.E. Gordon 《Radiation measurements》2012,47(1):57-66
A solid state nuclear track detector, CR-39, was exposed to DT neutrons. After etching, the resultant tracks were analyzed using both an optical microscope and a scanning electron microscope (SEM). In this communication, both methods of analyzing DT neutron tracks are discussed. 相似文献
2.
Using a field electron microscope and a field electron dispersion energy analyzer, carbon nanocrystals contained in polyacrylonitrile (PAN) fibers are studied. Transition of the emitting nanocrystals into the second stable state has been discovered, corresponding to an emission current and field electron energy distribution of magnitudes lower by nearly an order of magnitude, with an additional low-energy peak. Heating the samples at 750° C restores the initial characteristics of the field electron energy distribution and current-voltage characteristics of the nanocrystals. The forbidden bandwidth of the nanocrystals has been determined. 相似文献
3.
P.L. Stöhr 《Physics letters. A》1981,86(2):120-122
A superconductor driven into a nonequilibrium state under electron beam irradiation emits phonons. They can be detected by a spatially separated superconductor of the same material. This phenomenon, which is typical only to be superconducting state, is used to map a superconductor in a scanning electron microscope. 相似文献
4.
The variation of surface state of SUS-304L stainless steel with heat treatment in a vacuum of 10?9 Torr was observed by the ultra high vacuum low energy scanning electron microscope (UHVLESEM) by detecting the absorption electron current. The absorption electron current was very sensitive to the surface state and a large effect of the electron beam irradiation was observed. The variation of the absorption electron current with the surface segregation was measured within a microscopical dimension of 0.3 microm on a selected area of the scanning electron microscopic image. At the same time, the surface state was characterized by Auger electron spectroscopy and relations between surface states and the absorption electron current were discussed in relation to the secondary electron and backscattered electron yields. 相似文献
5.
采用电子束蒸发法沉积LaNi/Mg多层膜,再于350℃真空退火合金化的方法制备了厚度为375nm的LaMg2Ni合金薄膜.在吸、放氢过程中,该合金薄膜能够在高反射的金属态和透明的半导体态之间可逆地转变.在可见光波长范围内的平均透射率和电阻率在反射态和透明态之间的对比度大于104.利用扫描电子显微镜和原子力显微镜观察了吸放氢前后薄膜的表面及剖面形貌.结果表明,在氢化过程中薄膜表面的平整性降低且不可恢复,是脱氢态中出现低反射现象的主要原因.
关键词:
薄膜
光电性能
氢
形貌 相似文献
6.
Martin P?eni?ka Martina Tesa?ová Jakub Tě?itel Jana Nebesá?ová 《Micron (Oxford, England : 1993)》2010,41(5):455-460
In this study three types of scanning electron microscopes were used for the size determination of spermatozoa of sterlet Acipenser ruthenus – high vacuum scanning electron microscope (SEM, JEOL 6300), environmental scanning electron microscope (ESEM, Quanta 200 FEG), field emission scanning electron microscope (FESEM, JEOL 7401F) with cryoattachment Alto 2500 (Gatan) and transmission electron microscope (TEM, JEOL 1010). The use of particular microscopes was tied with different specimen preparation techniques. The aim of this study was to evaluate to what degree the type of used electron microscope can influence the size of different parts of spermatozoa. For high vacuum SEM the specimen was prepared using two slightly different procedures. After chemical fixation with 2.5% glutaraldehyde in 0.1 M phosphate buffer and post-fixation by 1% osmium tetroxide, the specimen was dehydrated by acetone series and dried either by critical point method or by means of t-butylalcohol. For ESEM fresh, unfixed material was used, which was dropped on microscopic copper grids. In FESEM working in cryo-mode the specimen was observed in a frozen state. Ultrathin sections from chemically fixed and Epon embedded specimens were prepared for TEM observation. Distinct parts of sterlet spermatozoa were measured in each microscope and the data obtained was statistically processed. Results confirmed that the classical chemical procedure of specimen preparation for SEM including critical point drying method led to a significant contraction of all measured values, which could deviate up to 30% in comparison with values measured on the fresh chemically untreated specimen in ESEM. Surprisingly sperm dimensions determinated on ultrathin sections by TEM are comparable with values obtained in ESEM or FESEM. 相似文献
7.
Yu. A. Novikov 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2013,7(6):1277-1282
A method for measuring the electron density distribution in the probe of a low voltage scanning electron microscope is described. It is shown that the focused electron probe of an S 4800 scanning electron microscope at the electron energy of 200 eV has a Gaussian shape of the electron density with the effective diameter of the probe of 20 nm. 相似文献
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This paper presents the design of a low voltage time of flight electron emission microscope (TOF-EEM), which should in principle be capable of acquiring spectral chemical information at nano-metre spatial resolution. The system will be able to operate as a photoelectron emission microscope (PEEM), an X-ray photoemission electron microscope (XPEEM), or a secondary electron emission microscope (SEEM). For each pixel in its highly magnified topographic image, the TOF-EEM column should be able to provide the emission spectrum with milli-electron-volt resolution. The system is designed to operate at secondary electron beam voltages of typically less than 100 V, and has the possibility of dynamically correcting for chromatic aberration. Provisional simulation results predict that the TOF-EEM column should be able to provide an image resolution of better than 2 nm. 相似文献
10.
对热扩散阴极表面微区发射状态进行原位观察和分析一直是热阴极研究的重要课题.本文着重介绍深紫外激光光发射电子/热发射电子显微镜的基本原理及其在热扩散阴极研究中的典型实例.系统配备了高温激活所用的加热装置,样品可被加热至1400℃.系统具有光发射电子、阴极热发射电子、光发射电子和阴极热发射电子联合三种电子成像模式.应用表明,对于热扩散阴极而言,深紫外激光光发射电子像适于呈现阴极表面的微观结构形貌;热发射电子像适于反映阴极表面的本征热电子发射及均匀性;光电子和热电子联合成像适于对阴极表面的有效发射点做出精确定位. 相似文献
11.
Ultrasound has been applied to an aqueous starch suspension and the erosion of starch grains that are free to move and whose dimensions approximate those of cavitational bubbles has been examined. The examination was carried out with a scanning electron microscope. The type of erosion (state of the surface and position and form of the pits) is analysed as a function of the experimental conditions — chiefly the type of surrounding gas: air, hydrogen, oxygen and carbon dioxide. 相似文献
12.
Focused electron beam induced deposition (FEBID) is a microscopic technique that allows geometrically controlled material deposition with very high spatial resolution. This technique was used to create a spiral aperture capable of generating electron vortex beams in a transmission electron microscope (TEM). The vortex was then fully characterized using different TEM techniques, estimating the average orbital angular momentum to be ∼0.8ℏ per electron with almost 60% of the beam ending up in the ℓ = 1 state. 相似文献
13.
S. Sengupta N. Halder S. Chakrabarti Miriam Herrera Marta Bonds Nigel D. Browning 《Superlattices and Microstructures》2009
Effect of growth pause or ripening time on structural and optical properties of self-assembled InAs/GaAs quantum dot (QD) heterostructures grown by solid state molecular beam epitaxy (MBE ) technique with two different growth rates of InAs (0.032 MLs−1 and 0.197 MLs−1) has been investigated. The QD heterostructures were grown at 520 °C with InAs monolayer coverage of 2.7 ML. The results were explained on the basis of high angle annular dark field scanning transmission electron microscope (HAADF-STEM), scanning electron microscope (SEM) and photoluminescence (PL) measurements. Introduction of growth pause leads the QD system towards a thermodynamic equilibrium state which in turn makes interesting changes on the morphology of the samples. Coagulation of some smaller dots occurs because of ripening to produce evolved QDs and the dot density reduces with growth pause. 相似文献
14.
W.X. Xia J.J. Kim T. Yogo D. Shindo M. Ito K. Ohashi 《Journal of magnetism and magnetic materials》2008
An electroless-plated CoFeNiB film as a soft underlayer in perpendicular magnetic recording is studied by magneto-optical Kerr effect microscope, magnetic force microscopy (MFM), and transmission electron microscopy. A stray field is evidently suppressed for the anisotropic CoFeNiB film, which is under an applied field during the plating process. The lines of magnetic flux show that the Ni seed layer have no intrinsic effect on the homogenous magnetic state of the CoFeNiB layer. The interaction between a MFM tip and the CoFeNiB layer is clearly observed by electron holography indicating the excellent soft magnetic properties required by the soft underlayer. 相似文献
15.
Samples with nodular defects grown from gold nanoparticles are prepared,and laser-induced damage tests are conducted on them.Nodular defects,which are in critical state of damage,are cross-sectioned by focusing on the ion beam and by imaging using a field emission scanning electron microscope.The crosssectional profile shows that cracks are generated and propagated along the nodular boundaries and the HfO2/SiO2 interface,or are even melted.The thermomechanical process induced by the heated seed region is analyzed based on the calculations of temperature increase and thermal stress.The numerical results give the critical temperature of the seed region and the thermal stress for crack generation,irradiated with threshold fluence.The numerical results are in good agreement with the experimental ones. 相似文献
16.
The properties of transition metal oxides are related to the presence of elements with mixed valences. The spectroscopy analysis of the valence states is feasible experimentally, but a spatial mapping of valence states of transition metal elements is a challenge to existing microscopy techniques. In this paper, with the use of valence state information provided by the white lines and near-edge fine structures observed using the electron energy-loss spectroscopy (EELS) in a transmission electron microscope (TEM), a novel experimental approach is demonstrated to map the valence state distributions of Mn and Co using the ratio of white lines in the energy-filtered TEM. The valence state map is almost independent of specimen thickness in the thickness range adequate for quantitative EELS microanalysis. An optimum spatial resolution of approximately 2 nm has been achieved for a two-phase Co oxides. 相似文献
17.
Y. Ino H. Soejima K. Hayakawa K. Yukihira K. Tanaka H. Fujita T. Watanabe K. Ogai K. Moriguchi Y. Harada Y. Yoshida 《Hyperfine Interactions》2016,237(1):13
A 3D-Mössbauer Spectroscopic Microscope is developed to evaluate Fe impurities in multi-crystalline Si solar cells, which combines the Mössbauer spectroscopic microscope with a scanning electron microscope (SEM), an electron beam induced current (EBIC), an electron backscatter diffraction (EBSD), and an electron energy analyzer (HV-CSA). In addition, a new moving-coil-actuator with a liner encoder of 100 nm-resolution is incorporated for the operations with both a constant velocity and a constant acceleration mode successfully with the same precision as that obtained by the conventional transducers. Furthermore, a new multi-capillary X-ray lens is designed to achieve a γ-ray spot size less than 100 μm in diameter. The new microscope provides us to investigate the space correlation between Fe impurities and the lattice defects such as grain boundaries in multi-crystalline Si solar cells. 相似文献
18.
In this paper, we show that a graphene quantum disk (GQD) can be generated on monolayer graphene via structural modification using the electron beam. The electronic structure and local optical responses of the GQD, supported on monolayer graphene, were probed with electron energy-loss spectrum imaging on an aberration-corrected scanning transmission electron microscope. We observe that for small GQD, ~1.3 nm in diameter, the electronic structure and optical response are governed by the dominating edge states, and are distinctly different from either monolayer graphene or double-layer graphene. Highly localized plasmon modes are generated at the GQD due to the confinement from the edge of the GQD in all directions. The highly localized optical response from GQDs could find use in designing nanoscale optoelectronic and plasmonic devices based on monolayer graphene. 相似文献
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