Superconductivity refers to the ability of an electric current to flow through a specific conductor without resistance. Superconductors are used in very few sectors such as magnetic levitation railways, particle accelerators in nuclear plants and magnetic resonance tomography.
Unconventional superconductors are materials that act as superconductors without having their mechanism understood by researchers. Conventional superconductors, on the other hand, do not super-conduct until far below the boiling point of nitrogen, which translates to somewhere between absolute zero and -234°C, or 39 Kelvin. Creating conventional superconductors whose transition temperature falls above the boiling point of nitrogen (77 Kelvin) remains elusive.
A group of researchers at the Laboratory of Crystallography at Eidgenössische Technische Hochschule in Zurich has, however, moved closer to this goal of creating conventional superconductors that operate at higher temperatures. This was demonstrated by developing new computational methods that enable the design of new superconducting materials through the prediction of their structures and properties.
For example, using computer-based calculations of germanium hydride (GeH4), it was shown that this substance is a conventional superconductor at 64 K. This still falls short of the 77 K mark; however, the researchers are already looking into doping the material with silicon or tin to overcome this limitation.
The researchers have the ambition of enabling new material discoveries by understanding the behaviour of materials under pressure, in particular, deep planetary interiors. They have discovered that germanium hydride will superconduct at relatively high temperatures, but will be simpler to process than the high-temperature superconductors that are currently available.
What makes this new technology significant is the ability to develop and predict new materials without any experimental knowledge. This could potentially create a big impact in terms of material design for researchers interested in the creation of new materials for superconductors. The application possibilities for this technology range from pharmaceuticals to superhard alloys and superconductors. The researchers have already been contacted by several industrial companies with a view to commercialising this technology.
The limiting factors for germanium hydride synthesis in particular include the need for high pressure (approximately two Megabars) to create the material, something that is not industrially possible at the moment. The researchers are also looking into predicting larger and more complicated structures such as nanoclusters, surfaces, interfaces and variable chemistry systems in addition to superconducting materials.
Any company interested in the development of new materials should be interested in this new technology, and this includes the fields of pharmaceuticals, electronic materials, nanotechnology, superhard materials and materials for alternative energies (for instance, hydrogen storage and solar cells). Once commercialised, this discovery could be a platform for new materials design, and further fuel the invention and creation of many new materials.
For more information contact Patrick Cairns, Frost & Sullivan, +27 (0)21 680 3274, [email protected], www.frost.com
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