As devices shrink, the proportion of surface area grows in comparison to the material's volume. Therefore, it's important to understand the characteristics of a material's surface in order to predict how those materials behave and how electrons will travel across an interface, said Brookhaven physicist John Hill.
Hill and his fellow researchers were particularly interested in how the outer electrons of atoms in a so-called manganite material are arranged. Manganites - consisting of a rare-earth element such as lanthanum combined with manganese and oxygen - show a huge change in electrical resistance when a magnetic field is applied. Taking advantage of this "colossal magnetoresistance effect" could be the key to developing advanced magnetic memory devices, magnetic field sensors, or transistors.
The research team, which also includes scientists from KEK (Japan), CNRS (France), Ames Laboratory, and Argonne National Laboratory, used x-ray scattering at Brookhaven's National Synchrotron Light Source and Argonne's Advanced Photon Source to study the orbital order - the arrangement of electrons in the outermost shell - of the material at the surface and in its bulk.
"When you cool down the bulk material to a particular temperature, all the orbitals arrange themselves in a very particular pattern," Hill said. "The question is, does the same thing happen at the surface? And if not, how is it different?"
The authors found that at the surface, the orbital order is more disordered than in the bulk material. And, even though the manganite's crystal surface is atomically smooth, the orbital surface is rough. These characteristics could affect the way electrons are transferred across a material's surface and provide fundamental information for future research and development. Next, the researchers plan to look for this surface orbital "roughness" in other materials and test its effect on magnetism.
Funding for this research was provided by the Office of Basic Energy Sciences within in the U.S. Department of Energy's Office of Science.
Karen McNulty Walsh | EurekAlert!
New method inverts the self-assembly of liquid crystals
15.04.2019 | University of Luxembourg
'Deep learning' casts wide net for novel 2D materials
11.04.2019 | Rice University
A stellar flare 10 times more powerful than anything seen on our sun has burst from an ultracool star almost the same size as Jupiter
A localization phenomenon boosts the accuracy of solving quantum many-body problems with quantum computers which are otherwise challenging for conventional computers. This brings such digital quantum simulation within reach on quantum devices available today.
Quantum computers promise to solve certain computational problems exponentially faster than any classical machine. “A particularly promising application is the...
The technology could revolutionize how information travels through data centers and artificial intelligence networks
Engineers at the University of California, Berkeley have built a new photonic switch that can control the direction of light passing through optical fibers...
Physicists observe how electron-hole pairs drift apart at ultrafast speed, but still remain strongly bound.
Modern electronics relies on ultrafast charge motion on ever shorter length scales. Physicists from Regensburg and Gothenburg have now succeeded in resolving a...
Engineers create novel optical devices, including a moth eye-inspired omnidirectional microwave antenna
A team of engineers at Tufts University has developed a series of 3D printed metamaterials with unique microwave or optical properties that go beyond what is...
17.04.2019 | Event News
15.04.2019 | Event News
09.04.2019 | Event News
18.04.2019 | Life Sciences
18.04.2019 | Physics and Astronomy
18.04.2019 | Life Sciences