Scientists study the pressure in Manganite towards "colossal magnetoresistance effect"

Scientists are studying a new phenomenon called "colossal magnetoresistance effect" (CMR), which is up to a thousand times more powerful than Giant Mmagnetoresistance effect (GMR) which is used in hard-drives today.

The researchers found that when a manganite was subjected to conditions above 230,000 times atmospheric pressure it underwent a transition in which its magnetic ordering changed from a ferromagnetic type (electron spins aligned) to an antiferromagnetic type (electron spins opposed). This transition was accompanied by a non-uniform structural distortion called the Jahn-Teller effect.

Magnetic ordering in manganit sketchMagnetic ordering in manganit sketch

“The results imply that even at ambient conditions, the manganite might already have two separate magnetic phases at the nanometer scale, with pressure favoring the growth of the antiferro-magnetic phase at the expense of the ferromagnetic phase,” said coauthor Daniel Haskel, a physicist at Argonne’s APS. “Manipulating phase separation at the nanoscale level is at the very core of nanotechnology and manganites provide an excellent playground to pursue this objective”

Posted: Jun 07,2009 by Ron Mertens