Now showing items 21-40 of 105

    • Energy-Filtered High-Resolution Electron Microscopy for Quantitative Solid State Structure Determination 

      Wang, Z. L. (Zhong Lin); Van Heerden, D.; Josell, D.; Shapiro, A. J. (Georgia Institute of TechnologyU.S. Dept. of Commerce, Technology Administration, National Institute of Standards and Technology, 1997)
      Energy-filtered (or selected) electron imaging is one of the future directions of highresolution electron microscopy (HREM). In this paper, the characteristics and applications of energy-selected electron imaging at ...
    • Liquid-phase synthesis of thiol-derivatized silver nanocrystals 

      Murthy, Srihari; Bigioni, Terry P.; Wang, Z. L. (Zhong Lin); Khoury, Joseph T.; Whetten, R. L. (Georgia Institute of Technology, 1997)
      A liquid-phase method is reported for the preparation of dodecanethiol-derivatized silver nanocrystals. Toluene sols of this material maintain as sols in air at room temperature at least on the timescale of months. X-ray ...
    • Studies of Mn valence conversion and oxygen vacancies in La₁₋ₓCaₓMnO₃₋[subscript y] using electron energy-loss spectroscopy 

      Wang, Z. L. (Zhong Lin); Yin, Jinsong; Jiang, Yongdong; Zhang, Jiming (Georgia Institute of TechnologyAmerican Institute of Physics, 1997-06-23)
      Using the white line intensities, electron energy-loss spectroscopy in a transmission electron microscope has been employed to characterize the valence conversion and oxygen vacancies in La₁₋ₓCaₓMnO₃₋[subscript y]. For a ...
    • Ordered Self-Assembling of Tetrahedral Oxide Nanocrystals 

      Yin, Jinsong; Wang, Z. L. (Zhong Lin) (Georgia Institute of TechnologyAmerican Physical Society, 1997-09-29)
      Self-assembling of size, shape, and phase controlled nanocrystals into superlattices with translational and even orientational ordering is a new approach for engineering nanocrystal materials and devices. High purity ...
    • Analysis of Cation Valences and Oxygen Vacancies in Magnetoresistive Oxides by Electron Energy-Loss Spectroscopy 

      Wang, Z. L. (Zhong Lin); Yin, Jinsong; Berta, Yolande; Zhang, Jiming (Georgia Institute of TechnologyMaterials Research Society, 1998)
      Magnetic oxides of (La,A)MnO₃ and (La,A)CoO₃ have two typical structural characteristics: cations with mixed valences and oxygen vacancies, which are required to balance the charge introduced by cation doping. The ...
    • Plasmon excitations in carbon onions: Model vs. measurements 

      Stöckli, Thomas; Wang, Z. L. (Zhong Lin); Bonard, Jean-Marc; Stadelmann, Pierre; Châtelain, André (Georgia Institute of TechnologyAmerican Institute of Physics, 1998-03)
      Non-relativistic local dielectric response theory has proven successful in the interpretation of Electron Energy Loss data of nanometer-size isotropic particles of different geometries. In previous work, we have adapted ...
    • Plasmon excitations in graphitic carbon spheres 

      Stöckli, Thomas; Bonard, Jean-Marc; Châtelain, André; Wang, Z. L. (Zhong Lin); Stadelmann, Pierre (Georgia Institute of TechnologyAmerican Physical Society, 1998-06-15)
      Electron energy loss spectroscopy in a high-resolution transmission electron microscope has recently been used with success to characterize the electronic properties of closed cage nanometer-size graphitic particles. In ...
    • Synthesis and characterization of Y₂O₃: Eu³⁺ powder phosphor by a hydrolysis technique 

      Jiang, Yongdong; Wang, Z. L. (Zhong Lin); Zhang, Fuli; Paris, Henry G.; Summers, Christopher J. (Georgia Institute of TechnologyMaterials Research Society, 1998-10)
      A forced hydrolysis technique is used for preparing Y₂O₃: Eu³⁺ powders at low processing temperatures. The technique uses yttrium oxide, europium oxide, nitric acid and urea, and has the potential for large-scale production ...
    • Low k, Porous Methyl Silsesquioxane and Spin-On-Glass 

      Kohl, Abbe T.; Mimna, Richard; Shick, Robert; Rhodes, Larry; Wang, Z. L. (Zhong Lin); Kohl, Paul A. (Georgia Institute of Technology, 1999)
      Low dielectric constant, porous silica was made from commercially available methyl silsesquioxane (MSQ) by the addition of a sacrificial polymer, substituted norbornene polymer containing triethoxysilyl groups (NB), to ...
    • Conductance quantization in multiwalled carbon nanotubes 

      Poncharal, P.; Frank, S.; Wang, Z. L. (Zhong Lin); De Heer, W. A. (Georgia Institute of Technology, 1999)
      We present results of carbon nanotube conductance measurements. The experiments were performed using an scanning probe microscope (SPM) system where a carbon nanotube fiber is connected to the SPM tip and then lowered ...
    • Synthesis of cobalt oxide nanocrystal self-assembled materials 

      Yin, Jinsong; Wang, Z. L. (Zhong Lin) (Georgia Institute of TechnologyMaterials Research Society, 1999-02)
      Self-assembling of size-, shape-, and phase-selected nanocrystals into superlattices is a new approach for synthesizing a new generation of advanced materials with functionality. In this paper, high purity and monodispersive ...
    • Synthesis and properties of Sr₂CeO₄ blue emission powder phosphor for field emission displays 

      Jiang, Yongdong; Zhang, Fuli; Summers, Christopher J.; Wang, Z. L. (Zhong Lin) (Georgia Institute of TechnologyAmerican Institute of Physics, 1999-03-22)
      A blue emission powder phosphor Sr₂CeO₄ for field emission displays was prepared using a chemical coprecipitation technique, which is most suitable for large-scale production. The powders were fired at different temperatures ...
    • Plasmon energy shift in mesoporous and double length-scale ordered nanoporous silica 

      Yin, Jinsong; Wang, Z. L. (Zhong Lin) (Georgia Institute of TechnologyAmerican Institute of Physics, 1999-05-03)
      Electron energy-loss spectroscopy studies are reported on three different types of structures: solid silica spheres, mesoporous silica, and the double length-scale ordered (DLSO) porous silica. The mesoporous silica has ...
    • Electron dynamics in gold and gold–silver alloy nanoparticles: The influence of a nonequilibrium electron distribution and the size dependence of the electron–phonon relaxation 

      Link, S.; Burda,  C.; Wang, Z. L. (Zhong Lin); El-Sayed, Mostafa A. (Georgia Institute of TechnologyAmerican Institute of Physics, 1999-07-15)
      Electron dynamics in gold nanoparticles with an average diameter between 9 and 48 nm have been studied by femtosecond transient absorption spectroscopy. Following the plasmon bleach recovery after low power excitation ...
    • Nanomeasurements of individual carbon nanotubes by in situ TEM 

      Wang, Z. L. (Zhong Lin); Poncharal, P.; De Heer, W. A. (Georgia Institute of TechnologyInternational Union of Pure and Applied Chemistry, 2000)
      Property characterization of nanomaterials is challenged by the small size of the structure because of the difficulties in manipulation. Here we demonstrate a novel approach that allows a direct measurement of the mechanical ...
    • Plasmon excitations in graphitic carbon spheres measured by EELS 

      Stöckli, Thomas; Bonard, Jean-Marc; Châtelain, André; Wang, Z. L. (Zhong Lin); Stadelmann, Pierre (Georgia Institute of Technology, 2000-02-15)
      The determination of the physical properties of individual nanometer-size particles has made rapid progress with the availability of local probe techniques during the past years. Electron energy-loss spectroscopy in a ...
    • Catalytically active nickel {110} surfaces in growth of carbon tubular structures 

      Kuang, MingHui; Wang, Z. L. (Zhong Lin); Bai, X. D.; Guo, J. D.; Wang, E. G. (Georgia Institute of TechnologyAmerican Institute of Physics, 2000-03-06)
      Recent interest in the growth of aligned carbon nanotube films using transition metal catalysts has led to questions concerning the growth mechanism involved. In our experiment carbon tubules grown using Ni catalysts exhibit ...
    • Direct synthesis of silicon nanowires, silica nanospheres, and wire-like nanosphere agglomerates 

      Gole, James L.; Stout, J. D.; Rauch, William L.; Wang, Z. L. (Zhong Lin) (Georgia Institute of TechnologyAmerican Institute of Physics, 2000-04-24)
      Elevated temperature synthesis has been used to generate virtually defect free SiO₂sheathed crystalline silicon nanowires and silica (SiO₂) nanospheres which can be agglomerated to wire-like configurations impregnated with ...
    • Nanomeasurements in Transmission Electron Microscopy 

      Wang, Z. L. (Zhong Lin); Poncharal, P.; De Heer, W. A. (Georgia Institute of TechnologyCambridge University Press, 2000-05)
      Nanomaterials have attracted a great deal of research interest recently. The small size of nanostructures constrains the application of well-established testing and measurement techniques, thus new methods and approaches ...
    • Configurations of misfit dislocations at interfaces of lattice-matched Ga₀.₅In₀.₅P/GaAs heterostructures 

      Wang, Y. Q.; Wang, Z. L. (Zhong Lin); Brown, Terence D.; Brown, A.; May, Gary S. (Georgia Institute of TechnologyAmerican Institute of Physics, 2000-07-10)
      A configuration of misfit dislocation dipoles is observed in a Ga0.5In0.5P heterostructure grown by solid-source molecular-beam epitaxy on GaAs. The dipole dislocations are mostly of 60° type, separated by ~3.5 nm. The ...