Nav: Home

Energy cascades in quasicrystals trigger an avalanche of discovery

December 12, 2016

Most materials, when viewed at the atomic level, come in one of two types. Some materials, like table salt, are highly crystalline, which means that the atoms in the material are arranged in orderly and repeating geometric patterns. Other materials, such as glass, display no such organization; in those cases, the atoms are arranged in what scientists call an amorphous structure.

A few special materials, however, straddle the line between crystalline and amorphous. These materials, known as quasicrystals, have atomic structures that are geometrically organized but, unlike those of crystalline materials, never repeat themselves. In a new study from the U.S. Department of Energy's (DOE's) Argonne National Laboratory, scientists looked at networks of magnetic material patterned into these unique and quite beautiful geometries to see how the nature of the nonrepeating patterns lead to the emergence of unusual energetic effects.

The simple but elegant geometric patterns within a quasicrystal are reminiscent of a stained-glass window or a Buddhist mandala. "Quasicrystals are scientifically interesting because their internal organization creates effects that you don't see in other materials," said Argonne senior materials scientist Amanda Petford-Long, who led the study.

Just as different pieces of glass come together along their edges to create shapes and patterns in a stained-glass window, a quasicrystal contains junctions that define its behavior. Although the junctions in a quasicrystal where different shapes come together can contain differing numbers of intersecting edges, each junction within a quasicrystal exhibits the same basic physical preference -- to be in the lowest energy state possible. However, because each point within the quasicrystal is constantly interacting and competing with its neighbors, not all of the vertices can be in their lowest energy states at the same time.

In the experiment, the Argonne researchers wanted to see how the quasicrystal's structure responded to adding some extra energy. "We were looking at whether we could actually transfer energy from one side of the lattice to the other, and to image the patterns that emerged when we tried to do so," said Argonne materials scientist Charudatta Phatak, another author of the study.

To their surprise, the researchers discovered that the redistribution of energy through the quasicrystal took place as a chain reaction that resembled the forked branches of a lightning strike. Unlike in a more conventional magnetic lattice, where these "avalanches" of energy redistribution occur only a single direction, the spread of redistributed energy throughout the lattice takes on a tree-like appearance.

Quasicrystals could provide one example of a system that scientists have been looking for: a network made up of magnetic islands that can propagate and store information. The behavior of these kinds of networks depends upon the amount of energy that is put into the system, according to Phatak.

Understanding the energetic behaviors of these kinds of networks is essential for the development of next-generation computational devices that could form the foundation of things like artificial neural networks, which would be able to perform complex computations with very low energy consumption.

A paper based on the study, "Real-space observation of magnetic excitations and avalanche behavior in artificial quasicrystal lattices," appeared in the October 3 online edition of Scientific Reports. The study was funded by the DOE Office of Science.
-end-
Argonne National Laboratory seeks solutions to pressing national problems in science and technology. The nation's first national laboratory, Argonne conducts leading-edge basic and applied scientific research in virtually every scientific discipline. Argonne researchers work closely with researchers from hundreds of companies, universities, and federal, state and municipal agencies to help them solve their specific problems, advance America's scientific leadership and prepare the nation for a better future. With employees from more than 60 nations, Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy's Office of Science.

The U.S. Department of Energy's Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, visit the Office of Science website.


DOE/Argonne National Laboratory

Related Behavior Articles:

Religious devotion as predictor of behavior
'Religious Devotion and Extrinsic Religiosity Affect In-group Altruism and Out-group Hostility Oppositely in Rural Jamaica,' suggests that a sincere belief in God -- religious devotion -- is unrelated to feelings of prejudice.
Brain stimulation influences honest behavior
Researchers at the University of Zurich have identified the brain mechanism that governs decisions between honesty and self-interest.
Brain pattern flexibility and behavior
The scientists analyzed an extensive data set of brain region connectivity from the NIH-funded Human Connectome Project (HCP) which is mapping neural connections in the brain and makes its data publicly available.
Butterflies: Agonistic display or courtship behavior?
A study shows that contests of butterflies occur only as erroneous courtships between sexually active males that are unable to distinguish the sex of the other butterflies.
Sedentary behavior associated with diabetic retinopathy
In a study published online by JAMA Ophthalmology, Paul D.
Curiosity has the power to change behavior for the better
Curiosity could be an effective tool to entice people into making smarter and sometimes healthier decisions, according to research presented at the annual convention of the American Psychological Association.
Campgrounds alter jay behavior
Anyone who's gone camping has seen birds foraging for picnic crumbs, and according to new research in The Condor: Ornithological Applications, the availability of food in campgrounds significantly alters jays' behavior and may even change how they interact with other bird species.
A new tool for forecasting the behavior of the microbiome
A team of investigators from Brigham and Women's Hospital and the University of Massachusetts have developed a suite of computer algorithms that can accurately predict the behavior of the microbiome -- the vast collection of microbes living on and inside the human body.
Is risk-taking behavior contagious?
Why do we sometimes decide to take risks and other times choose to play it safe?
Neural connectivity dictates altruistic behavior
A new study suggests that the specific alignment of neural networks in the brain dictates whether a person's altruism was motivated by selfish or altruistic behavior.

Related Behavior Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Anthropomorphic
Do animals grieve? Do they have language or consciousness? For a long time, scientists resisted the urge to look for human qualities in animals. This hour, TED speakers explore how that is changing. Guests include biological anthropologist Barbara King, dolphin researcher Denise Herzing, primatologist Frans de Waal, and ecologist Carl Safina.
Now Playing: Science for the People

#SB2 2019 Science Birthday Minisode: Mary Golda Ross
Our second annual Science Birthday is here, and this year we celebrate the wonderful Mary Golda Ross, born 9 August 1908. She died in 2008 at age 99, but left a lasting mark on the science of rocketry and space exploration as an early woman in engineering, and one of the first Native Americans in engineering. Join Rachelle and Bethany for this very special birthday minisode celebrating Mary and her achievements. Thanks to our Patreons who make this show possible! Read more about Mary G. Ross: Interview with Mary Ross on Lash Publications International, by Laurel Sheppard Meet Mary Golda...