Physicists find fractal boundaries in crystals

Sep 03, 2010 By Anne Ju
The top two images are two views of a computer-simulated fractal wall pattern after strain. The bottom two are micrographs taken from a single copper crystal and single aluminum crystal after strain.

Blacksmiths make horseshoes by heating, beating and bending iron, but what's happening to the metal's individual atoms during such a process? Cornell researchers, using computational modeling, are providing new insight into how atoms in crystals rearrange as the material is bent and shaped.

The researchers made computer-synthesized models of what such metals as aluminum and look like at the atomic level while being stretched, heated and cooled. They simulated how crystals, whose start in a regular grid, transform as they are bent into different shapes.

Such new theories could lead to a better understanding of structural materials, from buildings to bridges, to make them less susceptible to tearing or breaking.

"We're really at the beginning stages of trying to develop a systematic theory of how materials evolve as we vary strain and temperature," said James Sethna, Cornell professor of physics, who leads the research.

The work is published in the Sept. 1 edition (Vol. 105 Issue 10) of , a publication of the American Physical Society.

When a single crystal is bent, portions of the crystal shift and create defects in the lattice called dislocations. The researchers found that their crystals exhibited starkly contrasting properties depending on temperature.

When hot were bent, the dislocations arranged into grain boundaries, which are the places where lattice planes suddenly tilt. At low temperatures, the dislocations formed self-similar, random patterns known as fractals.

Explore further: Researchers find tin selenide shows promise for efficiently converting waste heat into electrical energy

Related Stories

Quasicrystal mystery unraveled with computer simulation

Mar 06, 2008

The method to the madness of quasicrystals has been a mystery to scientists. Quasicrystals are solids whose atoms aren't arranged in a repeating pattern, as they are in ordinary crystals. Yet they form intricate patterns ...

Paving the Way for Crystal Growth

Mar 07, 2007

In order to study the properties of LBCO superconductors, scientists need to produce large, single crystals of the material - a difficult task that wasn't possible until recently. At the state-of-the-art crystal ...

Recommended for you

Novel technique opens door to better solar cells

Apr 14, 2014

A team of scientists, led by Assistant Professor Andrivo Rusydi from the Department of Physics at the National University of Singapore's (NUS) Faculty of Science, has successfully developed a technique to ...

Probing metal solidification nondestructively

Apr 14, 2014

(Phys.org) —Los Alamos researchers and collaborators have used nondestructive imaging techniques to study the solidification of metal alloy samples. The team used complementary methods of proton radiography ...

User comments : 2

Adjust slider to filter visible comments by rank

Display comments: newest first

Kedas
5 / 5 (1) Sep 05, 2010
If they say that a and c is a match then they need glasses.
julesruis
not rated yet Sep 06, 2010
For more information about fractals, see:
http://www.fractal.org

More news stories

Better thermal-imaging lens from waste sulfur

Sulfur left over from refining fossil fuels can be transformed into cheap, lightweight, plastic lenses for infrared devices, including night-vision goggles, a University of Arizona-led international team ...

Robotics goes micro-scale

(Phys.org) —The development of light-driven 'micro-robots' that can autonomously investigate and manipulate the nano-scale environment in a microscope comes a step closer, thanks to new research from the ...

Hackathon team's GoogolPlex gives Siri extra powers

(Phys.org) —Four freshmen at the University of Pennsylvania have taken Apple's personal assistant Siri to behave as a graduate-level executive assistant which, when asked, is capable of adjusting the temperature ...