EM Navigator– 3D electron microscopy data navigator

Abstract

We find a striking distribution of inversion domains in a decagonal Al64Cu22Co14, which reveals a fractal-like, self-similar microstructure constructed by golden triangles (similar to a Sierpinski Gasket). This unique morphology of domains is confirmed to be thermodynamically stable configurations at high temperatures (> ~1200K), just below the melting temperature of the Al64Cu22Co14 compound. Details of the domain microstructure are described based on dark-field TEM imaging, convergent electron diffraction and atomic-resolution STEM. We propose that the occurrence of such self-similar domains may well be understood by concerning structural modulations extended into a hyperspace. Platinum (Pt) Palladium (Pd) nanoparticles supported on amorphous silica (SiO2) were prepared by wetness impregnation techniques at same concentrations of Pt(0.5) and Pd(0.5); 1 metallic wt %. The particle size distribution were measured as function of reaction temperature, temperatures were varied in the range of 200 -400 to evaluate the nucleation phenomena and thermal stability. In addition morphology and crystallinity under various reactor temperatures were investigated by physisorption Brunauer-EmmettTeller-(BET), X-Ray Diffraction (XRD), High Resolution Electron Microscopy (HREM) and Transmission Electron Microscopy (TEM). In this work, we observed the distribution of Pt and Pd in nanoparticles. The rational design of nanoscale structures for applications in technology increasingly relies on developing and improved understanding of processes, particularly in terms of how they contribute to the changing phase behavior of nanoscale systems. Crystal structures can be determined by X-ray, while transmission electron microscopy (TEM) is indispensable for characterization of nanocrystalline materials, because TEM is a tool that provides not only atomic resolution lattice images but also chemical information at a spatial resolution, allowing direct identification the chemistry of a single nanoparticle. Poly(heptamethylene terephthalate) (PHepT), which is one of aromatic polyesters, was synthesized, and its lamellar singlecrystals were grown isothermally, for example at 70 , from a dilute solution in 1-octanol. Nanofibers of PHepT were prepared via electro-spinning (apparatus: esprayer ES-1000 (Fuence Co., Ltd.; Tokyo, Japan)) of a solution in 1,1,1,3,3,3-hexafluoro-2-propanol. Morphology of the single crystals and that of as-spun and annealed nanofibers were investigated with a transmission electron microscope (JEOL JEM-200CS) which was operated at 200kV. Selected-area electron diffraction (SAED) of the crystals gives a well-defined N-pattern consisting of spot-like hk0 reflections, and that of a bandle of the annealed nanofibers gives a highly oriented fiber pattern. From the analysis of SAED patterns for both types of specimen, namely single crystals and nanofibers, it seems that PHepT takes an orthorhombic crystal system and its unit cell parameters are as follows: a = 1.409nm, b = 1.480nm, c (chain axis) = 3.392nm, α=β= γ=90 . In add...