Kinetically-stabilized Ferroelectricity in Bulk Singlecrystalline HfO2:Y without Wake-up Effects

Abstract

HfO2, a simple binary oxide, holds ultra-scalable ferroelectricity integrable into silicon technology. Polar orthorhombic (Pbc21) form in ultra-thin-films ascribes as the plausible root-cause of the astonishing ferroelectricity, which has thought not attainable in bulk crystals. Though, perplexities remain primarily due to the polymorphic nature and the characterization challenges at small-length scales. Herein, utilizing a state-of-the-art Laser-Diode-heated Floating Zone technique, we report ferroelectricity in bulk single-crystalline HfO2:Y as well as the presence of anti-polar Pbca phase at different Y concentrations. Neutron diffraction and atomic imaging demonstrate (anti-)polar crystallographic signatures and abundant 90o/180o ferroelectric domains in addition to the switchable polarization with little wake-up effects. Density-functional theory calculations suggest that the Yttrium doping and rapid cooling are the key factors for the desired phase. Our observations provide new insights into the polymorphic nature and phase controlling of HfO2, remove the upper size limit for ferroelectricity, and also pave a new road toward the next-generation ferroelectric devices.

34 pages. This is the original preprint before peer review. The final version has been accepted by Nature Materials

References in corpus (5)

• The Origin of Ferroelectricity in Hf${}_x$ Zr${}_{1-x}$ O${}_2$: A Computational Investigation and a Surface Energy Model
• A rhombohedral ferroelectric phase in epitaxially-strained Hf0.5Zr0.5O2 thin films
• Pathways Towards Ferroelectricity in Hafnia
• Antiferroelectricity in thin film ZrO2 from first principles
• Laser-diode-heated floating zone (LDFZ) method appropriate to crystal growth of incongruently melting materials

Cited by in corpus (14)

• Intrinsic ferroelectricity in Y-doped HfO2 thin films
• Epitaxial Ferroelectric HfO2 Films: Growth, Properties, and Devices
• Ferroelectricity in layered bismuth oxide down to 1 nanometer
• Piezoelectricity in hafnia
• Trilinear coupling driven ferroelectricity in HfO${}_2$
• Ferroelectricity in $\mathrm{Hf}{\mathrm{O}}_2$ from a chemical perspective
• Recent Advances in Unconventional Ferroelectrics and Multiferroics
• First-principles Calculations of Raman and Infrared Spectroscopy For Phase Identification and Strain Calibration of Hafnia
• Engineering ferroelectricity in monoclinic hafnia
• Finite-size effects on the ferroelectricity in rhombohedral HfO${}_2$
• Ferroelectric-HfO2/Oxide Interfaces, Oxygen Distribution Effect and Implications for Device Performance
• The anti-symmetric and anisotropic symmetric exchange interactions between electric dipoles in hafnia
• Antiferroelectricity with metastable polar state from Kittel model
• Anharmonic thermodynamics redefines metastability and parent phases in ferroelectric HfO2