Physicists harness effects of disorder in magnetic sensors
Date: Tuesday, September 09, 2008 @ 23:50:12 GMT Topic: Science
(PhysOrg.com) -- University of Chicago scientists have discovered how
to make magnetic sensors capable of operating at the high temperatures
that ceramic engines in cars and aircraft of the future will require
for higher operating efficiency than today's internal combustion
technology.
... Rosenbaum's research typically
focuses on the properties of materials observed at the atomic level
when subjected to temperatures near absolute zero (minus-460 degrees
Fahrenheit). More than a decade ago, he led a team of scientists in
experiments involving silver selenide and silver telluride, two
materials that exhibited no magnetic response at low temperatures. But
when the team introduced a tiny amount of silver (one part in 10,000)
to the materials, their magnetic response skyrocketed.
In silver selenide and silver telluride, the magnetic response
disappears at room temperature, which limits their technological
applications. But Rosenbaum and Hu now have used two methods to
recreate the effect at much higher temperatures in indium antimonide.
Disordering the material—simply grinding it up and fusing it with
heat—produces the effect. So does introducing impurities of just a few
parts per million.
...
Full article: http://www.physorg.com/news140202028.html
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