Ferroelectricity in the complementary metal-oxide semiconductor (CMOS)-compatible hafnia (HfO2) is crucial for the fabrication of high-integration nonvolatile memory devices. However, the capture of ferroelectricity in HfO2 requires the stabilization of thermodynamically-metastable orthorhombic or rhombohedral phases, which entails the introduction of defects (e.g., dopants and vacancies) and pays the price of crystal imperfections, causing unpleasant wake-up and fatigue effects. Here, we report a theoretical strategy on the realization of robust ferroelectricity in HfO2-based ferroelectrics by designing a series of epitaxial (HfO2)1/(CeO2)1 superlattices. The advantages of the designated ferroelectric superlattices are defects free, and most importantly, on the base of the thermodynamically stable monoclinic phase of HfO2. Consequently, this allows the creation of superior ferroelectric properties with an electric polarization >25 μC/cm2 and an ultralow polarization-switching energy barrier at ∼2.5 meV/atom. Our work may open an entirely new route towards the fabrication of high-performance HfO2 based ferroelectric devices.
@article{arxiv.2309.12800,
title = {Engineering ferroelectricity in monoclinic hafnia},
author = {Hong Jian Zhao and Yuhao Fu and Longju Yu and Yanchao Wang and Yurong Yang and Laurent Bellaiche and Yanming Ma},
journal= {arXiv preprint arXiv:2309.12800},
year = {2024}
}