In order to have efficient transmission lines for the electricity we seek to produce and ultimately use, it is imperative to change the old wires with something newer: superconductors. While searching for ways to make superconductors from various metals at extremely low pressures and low temperatures often failed to be practical, the thought of turning the hydrogen into a metallic state gives more and more clues of a nearby success.
A team of scientists from Cornell University and the State University of New York at Stony Brook announced this week in a specialized publication that they discovered, at least theoretically, how to turn hydrogen into a metal at significantly lower pressures than ever thought and make a superconductor out of it.
In their simulation, the scientists bonded hydrogen with lithium, which is the third lightest element in the universe, and got LiH. The simulation was made by a special software that theoretically combined hydrogen and lithium at different pressures, and obtained a result that was one quarter less (1 million atmospheres) than the temperature at which pure hydrogen turns metallic (3.4 million atmospheres).
The lithium and hydrogen combinations predicted by the study currently do not exist on Earth.
One of the combinations predicted by the team contains one lithium atom for every six hydrogen atoms or LiH6 (see top right image). The complex calculations predict that in the hypothetical compound the Li atom is triggered to release its lone outer electron, which is then distributed over the three H2 molecules.
Under pressure, the hypothetical reaction forms a stable and metallic hydrogen compound. The calculations also predict that LiH6 could be a metal at normal pressures. However, under these conditions it is not stable and would decompose to form LiH and H2.
“The stable and metallic LiH6 compound is predicted to form around 1 million atmospheres, which is around 25 percent of the pressure required to metalize hydrogen by itself,” said Eva Zurek, lead author of the paper and an assistant professor of chemistry at The State University of New York, Buffalo.