Credit: Image courtesy of R. Ramesh, Lawrence Berkeley National Laboratory
By controlling the layered structure, scientists observed discrete spiral regions in the ionic structure of multiple layered materials. The image shows an atomic-scale, high-resolution scanning transmission electron micrograph of the layered structures, with an overlay (yellow arrows) showing the local ionic movement, demonstrating the spiral configurations or “polar vortices.” The materials are made of very thin layers of electrically ordered lead titanate and electrically disordered strontium titanate.