Rising Stars Colloquium: Megan Holtz

Atomic structure, domain walls, and the design of multiferroic oxide superlattices

Materials that couple strong ferroelectric and ferromagnetic order provide new avenues to explore materials phenomena and hold tremendous promise for next-generation memory devices. Hexagonal oxide materials host emergent phenomena at topological defects such as vortices and domain walls, and are strong candidates for multiferroic materials design. Here we show with statistical atomic resolution mapping how dimensional confinement of domain walls stabilizes new topological textures beyond those found in bulk systems. We further construct multiferroic superlattices in which ferroelectricity and strong magnetic ordering are coupled at room temperature. These results, combining state of the art nanocharacterization of materials and devices with highly controlled atomic layer-by-layer growth, demonstrate a powerful paradigm for understanding functional materials systems and engineering them to design new devices.

Megan Holtz is a research professor at Colorado School of Mines, where she is developing scanning nanobeam electron diffraction techniques for quantum and ferroelectric materials. Previously, she was an NRC Postdoctoral Associate in the Materials Measurement Laboratory at NIST and as a postdoc and graduate student at Cornell University, where she used scanning transmission electron microscopy (STEM) and oxide molecular beam epitaxy (MBE) to investigate the fundamental properties of ferroelectric and multiferroic interfaces, as well as develop materials properties to bring them closer to device applications. She has authored and co-authored 27 papers, 3 of which have received over 100 citations, and she has given several invited talks at international conferences.