Sunday, September 11, 2011

Researchers discover superdense aluminum

An international research team has discovered a new material, superdense aluminum, which has never before been found on Earth.

In a paper published in Nature Communications, the researchers from Australia, the USA and Japan, describe how the material can only exist under extreme pressure, similar to that found in our planet's core.

According to team member Professor Saulius Juodkazis from Swinburne University of Technology, the researchers were able to create the superdense aluminum, which is around 40 per cent stronger and denser than its conventional counterpart, by simulating the conditions found at the center of Earth.

"At extreme pressures and temperatures, such as those found in our Earth's core, common materials form new dense phases with compacted atomic arrangements and unusual physical properties.

"Because we can't physically see or sample materials from the extreme depths of Earth, we need to come up with other ways to prove the existence of superdense materials. In this case, we replicated the high pressure conditions on a nano scale," he said.

"By focusing single short laser pulses of light onto a sapphire we were able to induce a micro explosion within it. This process mimics the kind of seismic forces that have shaped the Earth and other planets, melting and reforming materials under intense pressure, allowing us to synthesize the superdense aluminum material."

According to Professor Juodkazis, the discovery could significantly advance applications which rely on nanostructured materials.

"Using this focused laser technique, we may now be able create a range of superdense metals that have extraordinary properties," he said. "The creation of superdense silver or gold, for example, could lead to many new possibilities for bio-sensing and plasmonics."

He said the discovery was also likely to catch the attention of earth and climate scientists. "By examining the mechanical and electrical properties of this type of material, we may be able to gain a greater understanding of the electrical conductivity of the interior regions of the planet. This is particularly important in the context of global climate change observed over long geological time spans."

Professor Juodkazis said the experiment was conducted using a standard bench-top laser common in many research laboratories and manufacturing operations.

"Because of the simple nature of the experiment, other scientists will be able to replicate it without needing any sophisticated, expensive, equipment," he said. "As such, many researchers now have the means to create these high density, high pressure materials, opening the door to many exciting new possibilities."

The paper was authored by Dr Arturas Vailionis from Stanford University, Associate Professor Eugene Gamaly and Professor Andrei Rode from the Australian National University, Associate Professor Vygantas Mizeikis from Shizuoka University, Dr Wenge Yang from the Carnegie Institute of Washington and Professor Juodkazis from Swinburne.

Story Source:

The above story is reprinted (with editorial adaptations) from materials provided by Swinburne University of Technology.

Journal Reference:

Arturas Vailionis, Eugene G. Gamaly, Vygantas Mizeikis, Wenge Yang, Andrei V. Rode, Saulius Juodkazis. Evidence of superdense aluminium synthesized by ultrafast microexplosion. Nature Communications, 2011; 2: 445 DOI: 10.1038/ncomms1449

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