Iron-based superconductors respond well to pressure

Superconductivity—the ability of certain materials to conduct electricity with no resistance—continues to be one of the most challenging fields in materials science. On the one hand, the effect appears reliably in a number of materials, although only at very low temperatures. Those temperatures went up with the discovery of copper-based (cuprate) superconductors in 1986. In the last four years, iron-based superconductors have been developed and seen the maximum temperature of their superconducting transition pushed higher, although it's still cold compared to both the cuprates and room temperature. But the exact way in which these superconductors perform their tricks is still unclear.

One form of iron-based superconductors, the chalcogenides, are very unusual, since they are strongly magnetic—in other superconductors strong magnetism destroys the effect. ('Chalcogenide' is pronounced with a hard 'ch' as in 'chemistry', and refers to the presence of the chalcogenide element selenium.) Now, a new report in Nature indicates that they have another unusual property: high pressures, which normally kill superconductivity, can cause them to undergo a phase transition that not only restores the behavior, but raises the critical temperature.




Read the comments on this post