The multiferroic sandwich

September 04, 2015

Magnetism and ferroelectricity: two properties which are particularly important for technology. The former is well known in empirical uses: it makes the needle of the compass point towards the North Pole, a magnetic field can align magnetic moments called spin of the electrons that make up the material. The latter is the electric form of magnetism. Ferroelectric materials maintain electric polarization even after the electrical field that caused it is removed. The two properties are extremely useful, and would be even more so if they coexisted in the same material. At the moment one precludes the other: a material is either ferroelectric or magnetic.

Things may soon change. A new study conducted by SISSA and Northwestern University (Illinois, USA) published in the review Physical Review Letters, proposes a completely new model for creating these "multiferroic" materials.

"Ours is certainly not the first attempt at obtaining a material of this kind, but up to this point there has been little in terms of satisfying results," notes Massimo Capone, SISSA researcher and one of the authors of the study. "Our method is based on a surprising system." Capone and his colleagues' work is a theoretical study which will serve as a guide for developing the material itself.

"Our approach is based on creating a sort of sandwich with layers of Lithium Osmate, a ferroelectric metallic material, alternating with insulating material. Adding insulation causes magnetic properties to emerge from two non-magnetic materials. This arrangement, which we refer to in jargon as heterostructures, slows down electrons in the system, and it is this phenomenon that leads to the emergence of magnetism," explains Gianluca Giovanetti, SISSA/CNR IOM researcher, and one of the authors of the study.

"Our theoretical model shows a clear effect, and furthermore, we show that it is possible to control ferroelectricity with magnetism, another important property," concludes Capone. "The next step will be to test the material itself."

International School of Advanced Studies (SISSA)

Related Electrons Articles from Brightsurf:

One-way street for electrons
An international team of physicists, led by researchers of the Universities of Oldenburg and Bremen, Germany, has recorded an ultrafast film of the directed energy transport between neighbouring molecules in a nanomaterial.

Mystery solved: a 'New Kind of Electrons'
Why do certain materials emit electrons with a very specific energy?

Sticky electrons: When repulsion turns into attraction
Scientists in Vienna explain what happens at a strange 'border line' in materials science: Under certain conditions, materials change from well-known behaviour to different, partly unexplained phenomena.

Self-imaging of a molecule by its own electrons
Researchers at the Max Born Institute (MBI) have shown that high-resolution movies of molecular dynamics can be recorded using electrons ejected from the molecule by an intense laser field.

Electrons in the fast lane
Microscopic structures could further improve perovskite solar cells

Laser takes pictures of electrons in crystals
Microscopes of visible light allow to see tiny objects as living cells and their interior.

Plasma electrons can be used to produce metallic films
Computers, mobile phones and all other electronic devices contain thousands of transistors, linked together by thin films of metal.

Flatter graphene, faster electrons
Scientists from the Swiss Nanoscience Institute and the Department of Physics at the University of Basel developed a technique to flatten corrugations in graphene layers.

Researchers develop one-way street for electrons
The work has shown that these electron ratchets create geometric diodes that operate at room temperature and may unlock unprecedented abilities in the illusive terahertz regime.

Photons and electrons one on one
The dynamics of electrons changes ever so slightly on each interaction with a photon.

Read More: Electrons News and Electrons Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to