Your Smartphone, Made of Cement

MAY 29, 2013

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Close-up visualizations of (A) the HOMO and (B) LUMO single-particle electron states in the 64CaO glass. Both states are spin-degenerate, and h1 labels the cavity (cage) occupied by LUMO. Yellow and magenta stand for different signs of the wave-function nodes. (C) Simulation box and the electron spin-density of the 64CaO glass with one oxygen subtracted at h2—that is, with two additional electrons. The two electrons have the same spin and they occupy separate cavities, h1 (boundary, also shown in B) and h2 (center, location of removed oxygen), which are separated by 12 Å from each other. (D) Cage structure around the spin-density of one electron cor- responding to the h2 cavity (close-up from C). Al, gray; Ca, green; O, red.

From The Atlantic magazine

By Megan Garber

Straw into gold. Water into wine. Servant into princess. It's a longstanding obsession of human myth-making: turning one thing into another thing -- a lowly thing into a vaunted thing -- by way of miracle or magic.

Well, someone get Joseph Campbell. Because science has just found another way to bring the Rumpelstiltskin story to life. And to the life, specifically, of your electronics.

A collective of researchers from the U.S., Finland, Germany, and Japan, working with the U.S. Department of Energy, has developed a way to make metal out of the straw of the contemporary world: cement.

The process they discovered, published the Proceedings of the National Academy of Sciences, transforms liquid cement into a kind of glass-metal fusion that is exceptionally good at conducting heat and electricity. The resulting hybrid, the scientists say, can be used as a semiconductor in electronics: it offers good conductivity, low energy loss in magnetic fields, better resistance to corrosion than traditional metal, less brittleness than traditional glass, and fluidity for ease of processing and molding.

Which means that your gadgets — their liquid-crystal displays, their protective coatings, their computer chips — may soon be made, in part, of cement.

So how, exactly, do you turn masonry into metal? The scientists made use of a phenomenon known as electron trapping -- a condition that occurs when the free electrons in polycrystalline materials are, yep, "trapped" in the cage-like structures that form around them. 

The team, under Chris Benmore, a physicist from the U.S. Department of Energy [Office of Science's] Argonne National Laboratory, studied mayenite, a rare calcium aluminium oxide mineral that features, importantly, cubic symmetry. They melted the mayenite at temperatures of 2,000 degrees Celsius using carbon dioxide laser beam heating. They then processed the resulting liquid within different atmospheres to control the way oxygen would bond in the resulting glass. 

For that — and this was key — Argonne's Advanced Photon Source, led by a team under Benmore, developed a technique for suspending the material. The group used an aerodynamic levitator to levitate the hot liquid in the air, preventing it from touching container surfaces and forming crystals. The suspension, in turn, let the liquid cool, unimpeded, into a glassy state that could trap electrons in the form necessary for electronic conduction.

And voila! A glassy semi-conductor. Cement, made metallic. The scientists, from there, used a supercomputer to determine the best conditions for creating glass that could optimally conduct electricity at room temperature. [They confirmed the ideas in experiments using different x-ray techniques at SPring-8 in Japan combined with earlier measurements at the now-decomissioned Intense Pulsed Neutron Source at Argonne and at the Advanced Photon Source.]

The process may not be limited to glass, however. There could be other materials capable of transforming themselves into semiconductors through magic finely honed scientific techniques. "This phenomenon of trapping electrons and turning liquid cement into liquid metal was found recently, but not explained in detail until now," Benmore put it. "Now that we know the conditions needed to create trapped electrons in materials, we can develop and test other materials to find out if we can make them conduct electricity in this way."

The original Argonne National Laboratory press release, “The formula for turning cement into metal,” by Tona Kunz, can be read here.

This Argonne press release was also picked up by a multitude of media. Here’s a sampling:

The Advanced Photon Source at Argonne National Laboratory is one of five national synchrotron radiation light sources supported by the U.S. Department of Energy’s Office of Science to carry out applied and basic research to understand, predict, and ultimately control matter and energy at the electronic, atomic, and molecular levels, provide the foundations for new energy technologies, and support DOE missions in energy, environment, and national security. To learn more about the Office of Science x-ray user facilities, visit

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.