Quality superconductor can withstand high magnetic fields

“Our work here is important because not only have we demonstrated how to fabricate high quality KTaO3, but we have also shown that the material is capable of withstanding substantial magnetic fields without losing its desirable properties.”Kaveh Ahadi, North Carolina State University

By growing high-quality thin films of a superconductor called potassium tantalate (KTaO₃), researchers were able to discover that this material retains its superconductive characteristics even when exposed to extremely high magnetic fields. They report this work in papers in Nano Letters, Science Advances and the Journal of Vacuum Science & Technology A.

A superconductor is a material that can conduct electricity without any resistance – meaning none of the energy is dissipated as heat, for example. Superconductive materials could lead to the development of a variety of more efficient technologies, including faster computer components and more energy-efficient power devices. However, the field faces significant challenges. For example, many superconductive materials lose their superconductivity when exposed to magnetic fields, which limits their potential applications.

“Our work here is important because not only have we demonstrated how to fabricate high quality KTaO₃, but we have also shown that the material is capable of withstanding substantial magnetic fields without losing its desirable properties,” says Kaveh Ahadi, an assistant professor of materials science and engineering at North Carolina State University and corresponding author of the three papers. “Specifically, we found that KTaO₃ retains superconductivity even when exposed to magnetic fields up to 25 Tesla. This fundamental work is a necessary step toward the development of any potential applications for the material.”

The researchers were able to ‘grow’ KTaO₃ using a technique called molecular beam epitaxy, which effectively creates two-dimensional (2D) thin films of the material on a substrate by laying molecule-thin layers on top of one another with atomic-level precision. The resulting thin films have extremely high quality, meaning the molecular structure of the material has very few defects.

“These high-quality thin films are an ideal platform for studying the intrinsic properties of this materials system,” Ahadi says.

One such characterization study revealed that KTaO₃ thin films remained superconductive when exposed to magnetic fields of up to 25 Tesla. To put that in context, the only place in the US capable of generating a 25 Tesla magnetic field is the National High Magnetic Field Laboratory, which is where Ahadi and his collaborators tested the material.

“The research community is still in the early stages of understanding the superconductivity in KTaO₃, much less identifying applications for the material,” Ahadi says. “Our work here not only identifies one attractive quality that sets it apart from other 2D superconductors but provides a blueprint for how we can create KTaO₃ thin films that are well suited for performing the research necessary to understand intrinsic properties of this materials system.”

This story is adapted from material from North Carolina State University, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.