Wednesday, October 5, 2011

Nobel Prize: Chemistry

The Nobel Peace Prize in Chemistry was awarded to Israeli scientist, Dan Shechtman on October 5, 2011. Daniel Shechtman won for the discovery of quasicrystals. Most crystals are composed of a three-dimensional arrangement of atoms that repeat in an orderly pattern. Depending on their chemical composition, they have different symmetries. But quasicrystals behave differently than other crystals. They have an orderly pattern that includes pentagons, fivefold shapes, but unlike other crystals, the pattern never repeats itself exactly.

(This picture displays Israeli scientist, Daniel Shechtman, sits next to a transmission electron microscope at the Haifa Technion Institute of Technology in Israel on Wednesday.)

The existence of quasicrystals, though controversial, was anticipated much earlier, but Shechtman was the first to see them in nature. Shechtman first saw the startling image on April 8, 1982, while studying a rapidly chilled molten mixture of aluminum and manganese under an electron microscope. What he saw appeared to counter the laws of nature.

The finding was more than just theoretical. Quasicrystals have been used in surgical instruments, LED lights and non stick frying pans. They have poor heat conductivity, which makes them good insulators.
(The image above is an atomic model of a silver aluminum (AgAl) quasicrystal)

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