Create a superconducting material from a solvent

Superconductivity is a property of some materials that allows them to be induced to a state where the resistance to electricity disappears and the magnetic field becomes stronger. In this way, surprising applications can be achieved, such as magnetic levitation trains running in Japan. However, it is normal for this state to occur in metals. Research at Washington State University has made a non-metallic material, specifically carbon disulfide, become a superconductor, delving into what these properties can give themselves.

Carbon disulfide is a volatile liquid that acts as a solvent. The Washington State University research has carried out a transformation process so that this material acquire superconducting properties. Thus, what is a solvent becomes a highly capable medium for transmitting electric current, far surpassing conductive materials, which offer a certain resistance to electricity.

The research has been carried out by PhD student Ranga Dias and Chemistry professor Choong-Shik Yoo, and has been published in the journal Proceedings of the National Academy of Sciences. The experiment began three years ago, when it was studied how a white crystal reacted under a pressure comparable to that which exists near the Earth’s core. The material was transformed into a container to store energy, whose condensation was only surpassed by that which occurs in nuclear energy.

Then carbon disulfide came on the scene, which was also subjected to extreme conditions to achieve its superconductivity. “It is an important discovery that will attract a great deal of attention from many scientific communities, such as physics, chemistry and materials,” says Choong-Shik Yoo, Professor of Chemistry and Associate Director of the Institute for Shock Physics at Washington State University.

High pressure and cooled, carbon disulfide started acting like a metal. Properties such as magnetism, energy concentration and hardness appeared in it, the latter product of the restructuring of molecules, which unfolded in three dimensions in a similar way to what is found in diamonds.

The high pressure and the change in temperature brought the molecules closer to each other, facilitating a conductivity that only occurs in metals, due to their structure. In addition, the particles created a form of lattice or grating, through which the electrons move freely, thus eliminating all resistance to electricity. Experts believe that this discovery may facilitate the induction of this state in other materials without the need to reach extreme pressures and temperatures that touch absolute zero (-273 degrees Celsius).

Applications of superconductors

Professor Yoo is convinced of the usefulness of the work to advance in the field of superconducting materials. “This research will provide the vehicle for people to be intelligent when developing superconductors, understanding the fundamentals that guide them,” says the teacher.

Throughout the 20th century, various materials that acted as superconductors have been experimented on. In 1911, the Dutch scientist Heike Kamerlingh Onnes was the first to come face to face with the phenomenon, proving that mercury completely lost its electrical resistance when cooled to 4 degrees kelvin (-269 degrees centigrade). Although it would not be until later when the study of this type of materials progressed, together with a more organized experimentation.

Today, superconducting materials have applications in scientific research, but also in other aspects more linked to everyday life. They are used in the medical field for MRI tests, thanks to the electromagnetic behavior that they display, preventing or resisting the penetration of an external field.

Maglev trains, which circulate commercially in Japan and in areas of China such as Shanghai, are also based on the magnetic properties of superconductors. While some mobile phone stations use them for radio frequency and microwaves. In terms of research, particle accelerator systems, used to study physical phenomena, also contain these materials.

In the future, it is envisaged that superconductors can be used for energy storage and transmission, substantially improving current standards in this field and leading to super batteries. The propulsion of vehicles, as is already the case with magnetic levitation trains, is another of the applications that are envisaged.

Image: MohammadHasan