Physicists reveal novel magnetoelectric effect
New research at the Univ. of Arkansas (U of A) reveals a novel magnetoelectric effect that makes it possible to control magnetism with an electric field.
The novel mechanism may provide a new route for using multiferroic materials for the application of RAM (random access memories) in computers and other devices, such as printers.
An international research team, led by U of A physicists, reported its findings in an article appearing in Physical Review Letters.
The researchers studied a new predicted state of the multiferroic bismuth ferrite, a compound that can change its electrical polarization when under a magnetic field or magnetic properties when under an electric field. Because of these effects, bismuth ferrite interests researchers who want to design novel devices—based on magnetoelectric conversion.
The coupling mechanism in bismuth ferrite between magnetic order and electrical polarization order is required for this phenomenon to be clearly understood, said Yurong Yang, a research asst. prof. of physics in the J. William Fulbright College of Arts and Sciences.
“We discovered an unknown magnetoelectric switching mechanism,” Yang said. “In this mechanism, the magnetic order and electrical polarization are not coupled directly, they are coupled with oxygen octahedral tilting, respectively. The switching polarization by electric field leads to the change of the sense of the rotation of oxygen octahedral, which in turn induces the switching of the magnetic order.
“These two couplings are governed by an interaction between three different physical quantities, called ‘tri-linear coupling,’” he said. “In contrast with the trilinear-coupling effects in the literature, the new coupling involves a large polarization and thus can be easily tuned by an electric field.”
Source: Univ. of Arkansas