Context

• Scientists have discovered a new type of quasicrystal, one with 12-fold symmetry, in the Sand Hills of north central Nebraska, USA.

  • It’s also the first time that researchers have found a quasicrystal somewhere other than meteorites or the debris from nuclear blasts.

About Quasicrystal

• This quasicrystal was formed during an accidental electrical discharge, possibly by a lightning strike or a downed power line in a dune.
• Quasicrystal is essentially a crystal-like substance.
• However, unlike a crystal, in which atoms are arranged in a repeating pattern, a quasicrystal consists of atoms that are arranged in a pattern that doesn’t repeat itself regularly.
• For the longest time, physicists believed every crystalline arrangement of atoms must have a pattern that repeats itself perfectly over and over again.

  

• While studying diffraction patterns, which occur when X-rays are passed through the crystals, Shechtman noted “a regular diffraction pattern that did not match any periodically repeated structure”, and concluded that he has come across what are now known as quasicrystals, according to the Nobel Prize website. For his discovery, he was awarded a Nobel Prize in Chemistry in 2011.
• Since their discovery, quasicrystals have been widely created in labs and known to “possess novel electrical, photonic, and mechanical properties that aren’t found in other materials, making them an attractive prospect for materials scientists.
• Although quasicrystals can be easily produced, they are rarely found outside of the laboratory. The first one was identified in a meteorite, found in 2009 near the Khatyrka River in Chukhotka, Russia (in a fragment of the Khatyrka meteorite lying in the Koryak mountains of Russia)
• The second one was discovered in 2021 during the study of debris from the site of the world’s first nuclear explosion, which took place in 1945 in New Mexico.
• Scientists suggest that in both instances, for the formations of quasicrystals, materials were subjected to extremely high-pressure and high-temperature shock events.
• The latest discovery is only the third time that scientists have come across a quasicrystal in nature.
• Quasicrystals are crystals that have defied a peaceful logic of crystal formation in favour of less-than-optimum, more contested patterns.
• In order to create them that way, the forces that shape them need to constantly nudge them away from the form they would rather take, if left alone, and towards a form that they can take.
• It’s not unlike keeping a spring compressed between your fingers: the spring can be compressed but it would rather be relaxed, so it pushes against you, exerts a force demanding freedom from your oppression.
• By adopting a suboptimal crystal structure (an anthropocentric view, to be sure), quasicrystals offer a similar narrative: they may not be oppressed, kept in a state of stress, but the structure of their atomic lattice still contains the imprints of some stressful event.
• Further analysis revealed at least three varieties: two of an icosahedrite and a decagonite, later joined by a “quasicrystal approximant” called proxidecagonite.
• The crystal structure of icosahedrite exhibited fivefold symmetry in two dimensions: the pattern repeated itself after being rotated by 72º. (Icosahedrite exhibited 20-fold symmetry in three dimensions, thus its name). Decagonite exhibited 10-fold symmetry (36º).

Source: IE & The Hindu

Visit Abhiyan PEDIA (One of the Most Followed / Recommended) for UPSC Revisions: Click Here

IAS Abhiyan is now on Telegram: Click on the Below link to Join our Channels to stay Updated 

IAS Abhiyan Official: Click Here to Join

For UPSC Mains Value Edition (Facts, Quotes, Best Practices, Case Studies): Click Here to Join