BEIJING, March 16 (Xinhua) -- Researchers from China and Russia have bent the rules of classical chemistry and created superconducting compounds of hydrogen and rare-earth metal praseodymium.
Superconductors are materials capable of conducting electric current with no resistance. But the current superconductors can only work at very low temperatures and require extremely high pressure,limiting their application.
Scientists have been pursuing superconducting compounds at higher temperatures and lower pressures.
According to researchers from China's Jilin University and Skolkovo Institute of Science and Technology in Russia, they have been synthesizing compounds of hydrogen and praseodymium in a special chamber where the two were pressed between two cone-shaped diamonds and heated with a laser.
In previous studies, the researchers found that diamonds tend to break up when in contact with hydrogen. They replaced pure hydrogen with ammonium borane, a compound that can release a large amount of hydrogen when heated and reacts with praseodymium.
The researchers reported in the journal Science Advances that they found the new method more effective and created more new compounds with the method by increasing pressure.
The researchers have obtained PrH3 and PrH9 in which praseodymium packs with more hydrogen than classical chemistry allows for.
The analysis showed that the "outlaw" compounds are endowed with more properties. The researchers measured electrical resistance at different temperatures and pressures, finding that praseodymium hydride becomes superconducting at negative 264 degrees Celsius, much lower compared to other superconducting compounds with similar structures and chemical characteristics.
The researchers said they found new candidates for creating superconducting compounds and will continue to look for new high-temperature superconductors.
