Saturday, July 31, 2010

Strained Graphene Creates Pseudo-Magnetic Fields Stronger Than Any Before Seen | Popular Science

Strained Graphene Creates Pseudo-Magnetic Fields Stronger Than Any Before Seen | Popular Science: "Since scientists began studying magnetic fields more than 100 years ago, no one has been able to sustain big magnetic fields for very long. The record is 85 tesla -- a measurement of electromagnetism named for Nikola Tesla -- and it only lasted a few thousandths of a second. Make it stronger than that, and the magnets blow themselves apart.
But in Crommie's study, electrons inside carbon atoms behaved as if they were subjected to 300 tesla. It has to do with the way graphene is constructed, which leaves one out of every four valence electrons free to hop around. The other three electrons form tight hexagonal chains. When graphene sheets are strained -- for instance, when they're rolled up into carbon nanotubes or stretched into nanobubbles -- the bond lengths between atoms change, and electrons hop differently."

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