Phys.org November 19, 2021
Bubble-like domains, typically a precursor to the electrical skyrmions, arise in ultrathin complex oxide ferroelectric–dielectric–ferroelectric heterostructures epitaxially clamped with flat substrates. An international team of researchers (USA – Argonne National Laboratory, University of Arkansas, University of Chicago, Australia) peeled off heterostructure thin films containing electrical bubbles from the substrate, while keeping them fully intact. To establish that the bubble domains remained intact, they measured the capacitance and piezoelectric properties and found they stayed relatively stable up to a high voltage. The combination of experiment and simulation proved conclusively that these bubbles can live even when removed from the original substrate. When the bubbles were removed, the heterostructure film assumed a rippled appearance. They attributed the ripple formation to elastic energy at the free interfaces. They found that the bubbles were protected by a change in the materials’ built-in voltage. According to the researchers the findings could create the next generation of flexible microelectronic and energy storage devices… read more. TECHNICAL ARTICLE
… The two blue-white spots (4 nm radius) at the right side of the image indicate bubbles. Credit: Argonne National Laboratory.)