Aluminum was once more expensive than gold. As mankind began to develop the technology to pry the metal loose from it’s natural ore, we began to develop all kinds of uses for the light metal – aluminum foil, aluminum engine blocks, parts for aeroplanes, the list seemed endless. The metal was both strong and light, which made it ideal for so many applications.
Now, a recent result from Australia has uncovered a new form of aluminum. The results, published in the very prestigious journal Nature Communications, describes a form of aluminum that can only exist under intense pressure, the type of pressure that you might find at the center of a planet.
The research paper explains the experimental technique. In order to convince normal aluminum to become superdense, it had to be exposed to the types of conditions present at the center of the Earth – very high pressures and temperatures. It’s difficult to generate that type of environment in a research lab, but a focused laser technique made it possible. Short bursts from a powerful laser setup were trained on a sapphire target. Sapphire looks like a clear gemstone, but its chemical makeup is principally a mixture of aluminum and oxygen. When the sapphire absorbed the intense energy of the laser beam, a miniature explosion occurred within the gemstone, which for an instant mimicked the types of temperatures and pressures found at the center of the Earth. The result was a small amount of superdense aluminum, freed up from the aluminum oxide of the sapphire.
The resulting new form of aluminum had a density about 40% higher than normal aluminum. Because the way that the aluminum atoms are packed into their lattice determines their chemistry, it’s possible that this superdense aluminum will demonstrate vastly different chemistry compared to its normal, everyday counterpart. Because the experiment is so simple, large quantities of the superdense aluminum could (in principle) be prepared, and if things work out as well as the researchers hope, aluminum may soon experience a huge upsurge in interest from chemists and material scientists alike.
The source of this article can be found at: Vailionis, A.; Gamaly, E.G.; Mizeikis, V.; Yang, W.; Rode, Z.; Juodkazis, S. “Evidence of superdence aluminum synthesized by ultrafast microexplosion”. Nature Communications 2001, 2¸445.