Imagine that you could make a magnet out of plastic. Now imagine you can change its magnetism by shining colored lights on it.
That may seem far-fetched, as ridiculous as it may have once seemed that you could generate some kind of invisible waves and communicate with them over many miles. Yet radio waves are reality — and University of Utah and Ohio State University scientists really did develop a new plastic material whose magnetism can be "tuned" by colored light.
The researchers' discovery was published in the Feb. 4 issue of the scientific journal, Physical Review Letters, in an article with the impossible title "Photoinduced Magnetization in the Organic-Based Magnet Mc(TCNE)Xly(CH2Cl2)."
Authors from the U. are Joel S. Miller, distinguished professor in the chemistry department and adjunct professor of materials science, and Chitoshi Kitamura, who was a postdoctoral research assistant at the time of the study; and from Ohio State University, Columbus, Arthur J. Epstein and Dusan A. Pejakovic.
In their experiments, they developed a plastic that becomes 1.5 times more magnetic when exposed to blue light. Green light partially reverses the effect. Its value may lie in the development of light-controlled computer hardware, which could be much speedier than the present circuits.
The newly discovered plastic shows these strange properties only at temperatures of about minus 325 degrees Fahrenheit. Believe it or not, that's fairly warm by some scientific standards. According to Ohio State University, that temperature approaches that needed for "high-temperature" superconductors.
The project is part of a nearly 30-year scientific partnership between Miller and Epstein. They became collaborators after both started their scientific careers at the Xerox Corp. around the same time in the early 1970s. Since then, both moved on to other appointments, but they continue to work together.
Now that the researchers have proven they can make light-tunable plastic material, they can use what they know about organic chemistry to improve the properties, Epstein said in a prepared statement.
Someday soon, a material of this sort might operate at room temperature, opening the door to many applications.
"We're the pioneers" in making magnetic materials from organic and polymeric material, Miller noted. Some of these nonmetallic materials are able to perform at room temperature, others not.
If the discovery is to become more convenient, he said, "people are going to want something portable that they can carry around." This temperature range simply "isn't appropriate" for that, he said.
But in the process of creating earlier types of nonmetal magnetic material, they made the leap from extremely cold matter to room-temperature magnets.
So why would material change its magnetic properties according to the color of light shone on it? That's a scientific mystery.
"It has to do with the energy of the radiation. Different colors have different energies, and different energies respond differently in the molecule," Miller said.
"But to be honest with you, we really don't understand what's going on, to give you a definitive story."
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