Irreversible, plastic deformation causes extended crystalline defects in strontium titanate to organize into periodic structures, as revealed by neutron and X-ray scattering. These structures can enhance electronic properties such as superconductivity. Image: S. Hameed et al., University of Minnesota.In a surprising discovery, an international team of researchers, led by scientists at the University of Minnesota, found that deformations in a quantum material can cause imperfections in its crystal structure that can actually improve the material’s superconducting and electrical properties.
These ground-breaking findings, reported in a paper in Nature Materials, could provide new insights into the development of the next generation of quantum-based computing and electronic devices.
“Quantum materials have unusual magnetic and electrical properties that, if understood and controlled, could revolutionize virtually every aspect of society and enable highly energy-efficient electrical systems and faster, more accurate electronic devices,” said study co-author Martin Greven, a professor in the University of Minnesota’s School of Physics and Astronomy and director of its Center for Quantum Materials. “The ability to tune and modify the properties of quantum materials is pivotal to advances in both fundamental research and modern technology.”
Elastic deformation of materials occurs when the material is subjected to stress but returns to its original shape once the stress is removed. In contrast, plastic deformation is the non-reversible change of a material’s shape in response to an applied stress – or more simply, the act of squeezing or stretching a material until it loses its shape. Plastic deformation has been used by blacksmiths and engineers for thousands of years. An example of a material with a large plastic deformation range is wet chewing gum, which can be stretched to dozens of times its original length.
While elastic deformation has been extensively used to study and manipulate quantum materials, the effects of plastic deformation have not yet been explored. In fact, conventional wisdom would lead scientists to believe that 'squeezing' or 'stretching' quantum materials may remove their most intriguing properties.
In this pioneering study, the researchers used plastic deformation to create extended periodic defect structures in a prominent quantum material known as strontium titanate (SrTiO3). These defect structures induced changes in the material's electrical properties and boosted its superconductivity.
“We were quite surprised with the results,” Greven said. “We went into this thinking that our techniques would really mess up the material. We would have never guessed that these imperfections would actually improve the materials’ superconducting properties, which means that, at low enough temperatures, it could carry electricity without any energy waste.”
According to Greven, this study demonstrates the great promise of plastic deformation as a tool to manipulate and create new quantum materials. It could lead to novel electronic properties, including materials with high potential for applications in technology. He also said the study highlights the power of state-of-the-art neutron and X-ray scattering probes for deciphering the complex structures of quantum materials, and of a scientific approach that combines experiment and theory.
“Scientists can now use these techniques and tools to study thousands of other materials,” Greven said. “I expect that we will discover all kinds of new phenomena along the way.”
This story is adapted from material from the University of Minnesota, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.