‘Article Review- New experiments Produce Another Claim to Metallic Hydrogen.’
There has been another claim to metallic hydrogen by the use of a new experimental design. Hydrogen should become a metal when subjected to high pressures. However, it requires close to five million times ambient pressure to turn hydrogen to a metal, which made experiments difficult. In the new research carried out by Paul Loubeyre and colleagues, an anvil with a new type of squeezing surface was used (“Another Metallic Hydrogen Claim Made”). The team then measured the gradual changes in their hydrogen samples’ infrared absorption. IR spectra were measured above 400 GPa, which indicated that the hydrogen samples had turned to metal. Theoretical predictions support these results.
The results of this experiment were consistent with the metallic state of diatomic hydrogen molecules whose properties are the most sought after. To affirm to their findings in the research, researchers reported data showing the reverse changes as the pressure decreased.
Many experts have acknowledged Loubeyre’s experiment, most of whom were his competitors in the quest to make metallic hydrogen. However, not all experts found the results satisfactory as they believe that there could still be another explanation, including an interaction between hydrogen and anvil or another state of hydrogen. Nevertheless, Loubeyre’s group reached a higher pressure than other studies, which increases confidence in the findings.
To determine whether the metallic hydrogen was made, Mikhail Eremets suggests that measuring its conductivity is the surest way. The ultimate promise for metallic hydrogen is superconducting (“Another Metallic Hydrogen Claim Made”). Several conductivity tests on pressurized hydrogen have been made by Eremets to determine if the sample is conductive to absolute zero or it was superconducting. However, it has not been successful yet due to the difficulty of incorporating electrical leads into a diamond anvil experiment.
In the future, more studies on metallic hydrogen will come up. However, Russell Hemley believes that materials that have already been delivered, such as lanthanum hydride that are superconducting under room temperature are a more significant achievement to the study of hydrogen (Somayazulu et al.).