As I have mentioned in two previous blog posts, it is thought that around 2.6 million atmospheres of pressure will make hydrogen change its bonding so that it forms a metallic lattice. This metallic lattice is theorised to be a room temperature superconductor. Now British researchers have come closer to discovering whether this is true. A British team have used a diamond anvil cell to compress Hydrogen molecules to 3.5 million atmospheres, and they have observed hydrogen displaying properties not dissimilar to the properties predicted. It is now believed that a pressure of 4.5 million atmospheres will be required to turn hydrogen completely metallic. However the team are working with very small quantities of hydrogen, therefore at the moment the practical applications of the process are yet to be seen.
Sources; Image of diamond anvil cell and story:http://www.bbc.co.uk/news/science-environment-35237985