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SEM Shows (sem + shows)

Distribution by Scientific Domains

Polymers and Materials Science	50%

Selected Abstracts

Optical properties of ZnO nanotubes

CRYSTAL RESEARCH AND TECHNOLOGY, Issue 6 2010
Hongju Zhai
Abstract Tubular ZnO nanostructures have been obtained via a hydrothermal method at low temperature (90 °C) without any catalysts or templates. The XRD measurement reveals that the tubes are single crystals with hexagonal wurtzite structure. SEM shows that the diameters of ZnO nanotubes ranged from 400 to 550 nm. The Raman and PL spectra indicate that oxygen vacancies or Zn interstitials are responsible for the green emission in the ZnO nanotubes. A possible growth mechanism on the formation of crystalline ZnO nanotubes has been presented. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Simple Synthesis of Submicrometer Lead Titanate Powder by Precipitation of TiO2 Precursor on PbO Particulates

JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 4 2000
Kyoung R. Han
A simple way to prepare phase-pure, submicrometer PbTiO3 powder was tried by precipitation. Precipitation was carried out in an aqueous PbO slurry using aqueous TiCl4 and dilute NH4OH at pH 9.5 ± 0.1. The TG/DSC curves of the PT precursor show weight loss of ,7% and two exotherms at 492° and 522°C. They are attributed to the crystallization of tetragonal PbTiO3. XRD shows that tetragonal PbTiO3 can be obtained by heat treatment around 500°C via a noncrystalline state. SEM shows that the PbTiO3 powder calcined at 600°C for 1 h is well crystallized and in the range of 100,300 nm. [source]

Optimizing environmental scanning electron microscopy of spheroidal reaggregated neuronal cultures

MICROSCOPY RESEARCH AND TECHNIQUE, Issue 11 2008
Ivan S. Uroukov
Abstract Electrophysiological recordings from hen embryo brain spheroidal reaggregates on penetrating 3D multielectrode arrays could be understood more easily if the surface structure was known in more detail. Electrophysiological activity, as grouped spikes in trains, is acquired from spheroids, indicating the inner formation a neuronal network. To this end, spheroids can be observed by environmental scanning electron microscopy. Live spheroids collapse when the supporting water is evaporated. By careful adjustment of the chamber pressure it is possible to observe fully hydrated fixed spheroids. A thin film of water tends to prevent a clear view of the surface detail. This can be evaporated to reveal the surface while taking steps to avoid both inadvertent shrinkage and rewetting. Conventional SEM shows a very different surface that is rich in protruding cell bodies and fibers. The images are compared and interpreted with some images of the surface using transmission electron microscopy. Microsc. Res. Tech., 2008. © 2008 Wiley-Liss, Inc. [source]

Double Wall Carbon Nanotubes with an Inner Diameter of 0.4 nm

CHEMICAL VAPOR DEPOSITION, Issue 3 2003
L. Ci
Selective preparation of double wall carbon nanotubes (DWCNTs) is achieved by a floating iron catalyst CVD method with sufur promotion. SEM shows that the product consists of entangled nanotubes. HRTEM and Raman scattering have revealed that the smallest inner diameter of as-grown carbon nanotubes is 0.4 nm (see Figure). The smallest diameter is found to be produced at the low carbon partial pressure with low sulfur content. [source]