Thursday, October 6, 2011

Daniel Shechtman wins Chemistry Nobel


Israeli scientist Daniel Shechtman won the 2011 Nobel Prize in Chemistry on Wednesday for his discovery of quasicrystals, a mosaic-like chemical structure that researchers previously thought was impossible.
The Royal Swedish Academy of Sciences said Prof. Shechtman’s discovery in 1982 fundamentally changed the way chemists look at solid matter. It initially faced strong objections from the scientific community, and even got him kicked out of his research group.
Contrary to the previous belief that atoms were packed inside crystals in symmetrical patterns, Prof. Shechtman showed that the atoms in a crystal could be packed in a pattern that could not be repeated, the academy said.
He was studying a mix of aluminium and manganese in his microscope when he found a pattern similar to Islamic mosaics that never repeated itself and appeared contrary to the laws of nature.
Since then, quasicrystals have been produced in laboratories and a Swedish company found them in one of the most durable kinds of steel, which is now used in products such as razor blades and thin needles made specifically for eye surgery, the citation said. Scientists are also experimenting with using quasicrystals in coatings for frying pans, heat insulation in engines, and in light-emitting devices called LEDs.
They were discovered in nature for the first time in 2009, according to the citation.
Crystallographers always believed that all crystals have rotational symmetry, so that when they are rotated, they look the same. In 1982, in Washington, D.C., Prof. Shechtman first observed crystals with 10 points pentagonal symmetry, which most scientists said was impossible.
“I told everyone who was ready to listen that I had material with pentagonal symmetry. People just laughed at me,” Prof. Shechtman said in a description of his work released by his university.
For months he tried to persuade his colleagues of his find, but they refused to accept it. Finally he was asked to leave his research group.
Prof. Shechtman returned to Israel, where he found one colleague prepared to work with him on an article describing the phenomenon. The article was at first rejected, but finally published in November 1984 to uproar in the scientific world. Double Nobel winner Linus Pauling was among those who never accepted the findings.
“He would stand on those platforms and declare, ‘Danny Shechtman is talking nonsense. There is no such thing as quasicrystals, only quasi-scientists,” Prof. Shechtman said.
In 1987, friends of Prof. Shechtman in France and Japan succeeded in growing crystals large enough for x-rays to repeat and verify what he had discovered with the electron microscope.
The Nobel Prize in Chemistry announcement capped this year’s science awards.

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