Extended defects unlock new properties in nanomaterials

Materials scientists at the University of Minnesota Twin Cities have found a way to create and control tiny “flaws” inside ultra-thin materials. These internal features, known as extended defects, could give next-generation nanomaterials entirely new properties, opening the door to advances in nanotechnology.

The study, published in Nature Communications, demonstrated that patterned regions of the material could achieve a density of extended defects—atomic-scale disruptions in the crystal lattice—up to 1,000 times higher than in unpatterned areas.

“These extended defects are exciting because they span the entire material but occupy a very small volume,” said Andre Mkhoyan, a professor in the University of Minnesota Department of Chemical Engineering and Materials Science and senior author of the study. “By carefully controlling these tiny features, we can leverage the properties of both the defect and the surrounding material.”

This level of control means researchers can now design materials where different sections have dramatically different defect densities and types, potentially leading to new functionalities. By putting a very high concentration of defects along the material’s thickness, they can create new films where nanometer-sized patterns are completely dominated by the defects, leading to revolutionary material properties.

“We figured out a new way to design materials by making tiny, defect-inducing patterns on the substrate surface before growing thin film on it,” said Supriya Ghosh, a graduate student in the Mkhoyan Lab and first author on the paper.

This breakthrough provides a way to control tiny internal features in materials. Although the study focused on perovskite oxides, the researchers say the method could work with different types of thin materials. The hope is that someday electronic devices could take advantage of these defects.

In addition to Mkhoyan and Ghosh, the University of Minnesota team included Jay Shah, Silu Guo, Mayank Tanwar, Donghwan Kim, Sreejith Nair, Matthew Neurock, Turan Birol and Bharat Jalan, from the Department of Chemical Engineering and Materials Science along with Fengdeng Liu who has additional ties to the Department of Electrical and Computer Engineering.