Last year, 2019, there was a lot of excitement at the news that a team of researchers demonstrated superconductivity property (flow of electricity with no resistance) at a temperature of -23° Celsius (-9.4° Fahrenheit).
Superconductivity is the holy grail in energy use, it gets as close as you can to perpetual motion (impossible, trackof course). Basically it is about finding a material in which electricity could flow with no resistance. That means no dissipation of heat and no waste in the conductors. It is ideal to generate strong magnetic fields, like the one used for the MagLev (ultra high speed train) that reached 603 Km/h last year in an experimental setting in Japan.
The nice thing about a MagLev is that it is not subject to friction from the rails since it floats over them (but it is of course subject to air resistance) so that in principle it could use less power than a conventional train. The problem is that the generation of those huge magnetic fields requires plenty of electrical current and this in turns generates a lot of waste in form of heat.
With superconductor this problem is solved but today’s superconducting materials have this characteristics only at very low temperatures. Physicists have been able to increase the temperature thresholds from somewhere close to the absolute “zero” to the . This is already supporting a variety of industrial applications with a market that is expected to reach 1.4 billion $ by 2027. This market is focussing on niche applications where cost to refrigerate the material used for superconductivity is not an issue compared with the benefit they provide. Currently, we define as high temperature superconductors those materials that have this characteristics at a temperature greater than -196.2° Celsius (boiling point of liquid hydrogen). These materials are interesting because we have the capability of freezing them at those temperature (using liquid hydrogen!).
Now researchers at the university of Illinois at Chicago have demonstrated superconductivity properties at 15° Celsius in a material composed by carbon, sulphur and hydrogen when compressed by two diamond (look at the photo). The “pressure” that needs to be applied is of the order of 2.6 million times the normal atmospheric pressure, and this is the reason for using diamonds. Because of this high pressure the researchers have not been able to work out the actual composition of the material (the arrangement of its atoms):they demonstrated superconductivity but they do not know why it is created.
You may take this as a curiosity since the material is so tiny that it is difficult to imagine a practical application and the requisite of applying such pressure makes it quite difficult to achieve outside of a lab. However, the result is really impressive and it opens up to new studies that by leading to understand why such material becomes a superconductor can also find alternative solutions where much lower pressure can lead to the same result.