Resarchers analyse compound that can help detect weapons of mass destruction

September 27th, 2008 - 1:13 pm ICT by IANS  

Washington, Sep 27 (IANS) A light-transmitting compound with potential use in fibre optics and sensors to detect weapons of mass destruction like biological and chemical agents, went virtually undiscovered because its structure was too difficult to examine.Luckily, scientists from US Department of Energy’s Argonne National Laboratory and Northwestern University were able to determine the structure of the compound using the Chemistry and Materials beamline of the Centre for Advanced Radiation Sources (ChemMatCARS) at the Advanced Photon Source.

“Like other such materials, this material has an electrically polarised structure. The incident light interacts with the electron cloud and the process is disturbed,” Argonne scientist Mercouri Kanatzidis said.

“The disturbance changes the wavelength of the emitted light and creates two beams: the original and the second harmonic - a beam with half the wavelength and double the frequency.”

This second-harmonic beam is 15 times more intense than that produced by the best current material. This two-for-one wavelength boost is paired with greater transparency, so the material can actually transmit the whole higher-wavelength beam.

This could have eventual real-world applications in identifying biological and chemical weapons at long distances and in optical communications, according to a release of Argonne National Laboratory.

However, these properties almost went undiscovered. The material, (A)ZrPSe6, where A can be potassium, rubidium or cesium, has a unique and difficult chemical structure that does not crystallise very well.

It grows lengthwise, but not in other directions. This creates long, thin crystals, perfect for fibre optics but a headache to study by conventional means.

“They are not very easy to design or make,” Kanatzidis said. “It doesn’t like to grow in other directions.”

Finally, using ChemMatCARS at the APS, Kanatzidis and his team were able to determine the structure and analyse its remarkable properties.

Their work was published in a recent edition of the Journal of the American Chemical Society.

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