Chemistry Nexus

by WebElements: the periodic table on the web

A link to this article is here for historical interest. The paper is by Sir William Crookes and was published in 1914. It concerns efforts to record spectroscopic data of pure elemental silicon.1 One difficulty concerned finding a pure sample.

References

1. Crookes, W. “On the Spectrum of Elementary Silicon“. Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences.
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December 15th, 2009

Posted In: Chemistry, Spectroscopy

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For the last few days there have been many reports of damage to car oxygen sensors in England’s south east. This seems to have been cause by faulty fuel supplied by some supermarker chains, including Tesco and Morrison’s. Initial reports suggested the fuel was up to standard but one wonders if this is a consequence of not applying the correct tests.

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March 3rd, 2007

Posted In: Chemistry

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Workers at The University of Wisconsin-Madison in the USA have managed to release thin membranes of semiconductors from a substrate and transfer them to new surfaces.1

The freed membranes which are just tens of nanometers thick retain all the properties of silicon in wafer form but the nanomembranes are flexible. By varying the thicknesses of the silicon and silicon-germanium layers composing them, membrane shapes are possible ranging from flat to curved to tubular.Potential applications include flexible electronic devices, faster transistors, nano-size photonic crystals that steer light, and lightweight sensors for detecting toxins in the environment or biological events in cells.The scientists made a three-layer nanomembrane composed of a thin silicon-germanium layer sandwiched between two silicon layers of similar thinness.

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June 2nd, 2006

Posted In: Chemistry, Materials chemistry, Nanoscience and nanotechnology

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This is interesting. NASA scientists are examining a seemingly magical way to produce high-quality crystals.

Perhaps a NASA laboratory is an unlikely setting for a magic show. Nevertheless, this is where Frank Szofran and colleagues are growing high-quality crystals using a method as amazing as any conjuring trick. By carefully cooling a molten germanium-silicon mixture inside a cylindrical container, they coax it into forming a single large and extraordinarily well-ordered crystal.

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December 11th, 2001

Posted In: Chemistry

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