Effects of Strain and Film Thickness on the Stability of the Rhombohedral Phase of HfO2

Abstract

The discovery of ferroelectric polarization in HfO2-based ultrathin films has spawned a lot of interest due to their potential applications in data storage. Recently, a new R3m rhombohedral phase was proposed to be responsible for the emergence of ferroelectricity in the [111]-oriented Hf0.5Zr0.5O2 thin films, but the fundamental mechanism of ferroelectric polarization in such films remains poorly understood. In this paper, we employ density-functional-theory calculations to investigate structural and polarization properties of the R3m HfO2 phase. We find that the film thickness and in-plane compressive strain effects play a key role in stabilizing the R3m phase leading to robust ferroelectricity of [111]-oriented R3m HfO2.

13 pages, 5 figures

References in corpus (3)

• The Origin of Ferroelectricity in Hf${}_x$ Zr${}_{1-x}$ O${}_2$: A Computational Investigation and a Surface Energy Model
• Pathways Towards Ferroelectricity in Hafnia
• Engineering Ferroelectric Hf0.5Zr0.5O2 Thin Films by Epitaxial Stress

Cited by in corpus (10)

• Epitaxial Ferroelectric HfO2 Films: Growth, Properties, and Devices
• Domain Matching Epitaxy of Ferroelectric Hf0.5Zr0.5O2(111) on La2/3Sr1/3MnO3(001)
• Stabilization of competing ferroelectric phases of HfO${}_2$ under epitaxial strain
• Trilinear coupling driven ferroelectricity in HfO${}_2$
• Progress in Computational Understanding of Ferroelectric Mechanisms in HfO${}_2$
• Ferroelectricity in epitaxially strained rhombohedral ZrO2 thin films
• Stabilization of the epitaxial rhombohedral ferroelectric phase in ZrO2 by surface energy
• Disentangling stress and strain effects in ferroelectric HfO2
• Epitaxial ferroelectric hafnia stabilized by symmetry constraints
• Finite-size effects on the ferroelectricity in rhombohedral HfO${}_2$