At 72,000,000 psi (500 GPa) hydrogen will undergo a state change to "metallic hydrogen" that exhibits the properties of a metal. 400 GPa is predicted to be the melting point for compressed hydrogen, which would create liquid metal hydrogen. And Neil Ashcroft hypothesized that metallic hydrogen (including liquid metal hydrogen) could be a superconductor at room temperature. This comes from the fact that when compressed, hydrogen develops a tightly packed lattice structure. However, reaching these pressures has proven difficult to obtain. 51,000,000 psi (~350 GPa) was achieved, but hydrogen was found to be an insulator in those conditions. Higher pressure is needed.
University of Buffalo chemists Eva Zurek and Pio Baettig plan sidestep technological limitations by lessen the pressure needed to create metallic hydrogen. Adding sodium to hydrogen, 1 sodium atom for every 9 hydrogen, the team will significantly lower the pressure needed to make the state change. The pressure needed is now only 36,256,000 psi (250 GPa).
In 2009 Zurek was able to create the material LiH6 (lithium hydrogen solid) at 14,000,000 psi. Like NaH9 (metallic hydrogen), LiH6 is not found in a stable form in nature. At high pressures, the results are stable and predictable. The goal is to create a power transmission method with near zero loss as a result of using a superconductor. As well as to better understand chemicals/elements under extreme pressures.
Zurek explains, "if one could potentially metallize hydrogen using the addition of sodium, it could ultimately help us better understand superconductors and lead to new approaches to designing a room-temperature superconductor... One of the things that I always like to emphasize is that chemistry is very different under high pressures. Our chemical intuition is based upon our experience at one atmosphere. Under pressure, elements that do not usually combine on the Earth's surface may mix, or mix in different proportions. The insulator iodine becomes a metal, and sodium becomes insulating. Our aim is to use the results of computational experiments in order to help develop a chemical intuition under pressure, and to predict new materials with unusual properties."
Although power transmission will be zero loss, will the energy needed to maintain such high pressures be a complete loss in the end? I look forward to more research from the team at UB.
Eavesdropper
