The enhancement of the functional properties of materials at reduced dimensions is crucial for continuous advancements in nanoelectronic applications. Here, we report that the scale reduction leads to the emergence of an important functional property – ferroelectricity, challenging the long-standing notion that ferroelectricity is inevitably suppressed at the scale of a few nanometers. A combination of theoretical calculations, electrical measurements, and structural analyses provides evidence of room-temperature ferroelectricity in strain-free epitaxial nanometer-thick films of otherwise non-ferroelectric SrTiO3. We show that electrically-induced alignment of naturally existing polar nanoregions is responsible for the appearance of a stable net ferroelectric polarization in these films. This finding can be useful for the development of low-dimensional material systems with enhanced functional properties relevant to emerging nanoelectronic devices.
This is an author-produced, peer-reviewed version of this article. The final, definitive version of this document can be found online at Science, published by American Association for the Advancement of Science. Copyright restrictions may apply. doi: 10.1126/science.aaa6442.
Tenne, D. A.. (2015). "Emergence of Room-Temperature Ferroelectricity at Reduced Dimensions". Science, 349(6254), 1314-1317.