A rhombohedral ferroelectric phase in epitaxially-strained Hf0.5Zr0.5O2 thin films

Abstract

After decades of searching for robust nanoscale ferroelectricity that could enable integration into the next generation memory and logic devices, hafnia-based thin films have appeared as the ultimate candidate because their ferroelectric (FE) polarization becomes more robust as the size is reduced. This exposes a new kind of ferroelectricity, whose mechanism still needs to be understood. Towards this end, thin films with increased crystal quality are needed. We report the epitaxial growth of Hf0.5Zr0.5O2 (HZO) thin films on (001)-oriented La0.7Sr0.3MnO3/SrTiO3 (STO) substrates. The films, which are under epitaxial compressive strain and are predominantly (111)-oriented, display large FE polarization values up to 34 μC/cm2 and do not need wake-up cycling. Structural characterization reveals a rhombohedral phase, different from the commonly reported polar orthorhombic phase. This unexpected finding allows us to propose a compelling model for the formation of the FE phase. In addition, these results point towards nanoparticles of simple oxides as a vastly unexplored class of nanoscale ferroelectrics.

References in corpus (6)

• 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
• Phase transitions induced by confinement of ferroic nanoparticles
• Anomalous enhancement of tetragonality in PbTiO3 induced by negative pressure
• Ab initio Evidence for Giant Magnetoelectric Responses Driven by Structural Softness
• Crystal structure prediction using ab initio evolutionary techniques: principles and applications

Cited by in corpus (62)

• Intrinsic ferroelectricity in Y-doped HfO2 thin films
• Kinetically-stabilized Ferroelectricity in Bulk Singlecrystalline HfO2:Y without Wake-up Effects
• Engineering Ferroelectric Hf0.5Zr0.5O2 Thin Films by Epitaxial Stress
• Epitaxial Ferroelectric HfO2 Films: Growth, Properties, and Devices
• High polarization, endurance and retention in sub-5 nm Hf${}_{0.5}$Zr${}_{0.5}$O${}_2$ films
• Growth Window of Ferroelectric Epitaxial Hf0.5Zr0.5O2 Thin Films
• Structural Polymorphism Kinetics Promoted by Charged Oxygen Vacancies in HfO${}_2$
• Effects of Growth Orientations and Epitaxial Strains on Phase Stability of HfO${}_2$ Thin Films
• Ferroelectricity in layered bismuth oxide down to 1 nanometer
• 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
• Enhanced ferroelectricity in epitaxial Hf0.5Zr0.5O2 thin films integrated with Si(001) using SrTiO3 templates
• Epitaxial Ferroelectric La-doped Hf0.5Zr0.5O2 Thin Films
• Effects of Strain and Film Thickness on the Stability of the Rhombohedral Phase of HfO2
• Design of a multifunctional polar metal via first-principles high-throughput structure screening
• Direct epitaxial growth of polar (1-x)HfO2-(x)ZrO2 ultra-thin films on Silicon
• Guidelines for the stabilization of a polar rhombohedral phase in epitaxial Hf0.5Zr0.5O2 thin films
• Polarization and resistive switching in epitaxial 2 nm Hf${}_{0.5}$Zr${}_{0.5}$O${}_2$ tunnel junctions
• Blocking of conducting channels widens window for ferroelectric resistive switching in interface-engineered Hf0.5Zr0.5O2 tunnel devices
• Epitaxial Integration on Si(001) of Ferroelectric Hf0.5Zr0.5O2 Capacitors with High Retention and Endurance
• Unraveling ferroelectric polarization and ionic contributions to electroresistance in epitaxial Hf0.5Zr0.5O2 tunnel junctions
• 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
• Critical Effect of Bottom Electrode on Ferroelectricity of Epitaxial Hf0.5Zr0.5O2 Thin Films
• Magnetic tunnel junctions based on ferroelectric Hf0.5Zr0.5O2 tunnel barriers
• Stabilization of phase-pure rhombohedral HfZrO4 in Pulsed Laser Deposited thin films
• Magneto-ionic control of spin polarization in magnetic tunnel junctions
• Strain engineering of epitaxial oxide heterostructures beyond substrate limitations
• A CMOS-compatible morphotropic phase boundary
• Shift current response in elemental two-dimensional ferroelectrics
• Stabilization of the epitaxial rhombohedral ferroelectric phase in ZrO2 by surface energy
• Fatigue and retention in the growth window of ferroelectric Hf0.5Zr0.5O2 thin films
• Controllable Defect Driven Symmetry Change and Domain Structure Evolution in BiFeO3 with Enhanced Tetragonality
• Effect of dopant ordering on the stability of ferroelectric hafnia
• Epitaxial ferroelectric hafnia stabilized by symmetry constraints
• Flexoelectricity-stabilized ferroelectric phase with enhanced reliability in ultrathin La:HfO2 films
• Electro-optic properties of ZrO2, HfO2 and LiNbO3 ferroelectric phases: A comprehensive and comparative study with density functional theory
• Recent Advances in Unconventional Ferroelectrics and Multiferroics
• Origin of Interstitial Doping Induced Coercive Field Reduction in Ferroelectric Hafnia
• Electrochemical control of ferroelectricity in hafnia-based ferroelectric devices using reversible oxygen migration
• Theoretical lower limit of coercive field in ferroelectric hafnia
• Symmetry of ferroelectric switching and domain walls in hafnium dioxide
• 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
• Negative capacitance overcomes Schottky-gate limits in GaN high-electron-mobility transistors
• High-Conductance, Ohmic-like HfZrO${}_4$ Ferroelectric Memristor
• Polarization boost and ferroelectricity down to one unit cell in layered Carpy-Galy La${}_2$Ti${}_2$O${}_7$ thin films
• Superconductor discovery in the emerging paradigm of Materials Informatics
• Unexpected large electrostatic gating by pyroelectric charge accumulation
• Investigating the Electromechanical Behavior of Unconventionally Ferroelectric $H{f}_{0.5}Z{r}_{0.5}{O}_2$-based Capacitors Through Operando Nanobeam X-ray Diffraction
• Tunneling Anisotropic Magnetoresistance in Ferroelectric Tunnel Junctions
• Operando observation of reversible oxygen migration and phase transitions in ferroelectric devices
• Antiferroelectricity with metastable polar state from Kittel model
• Guidelines for the optimization of hafnia-based ferroelectrics through superlattice engineering
• Sliding and superlubric moiré twisting ferroelectric transition in HfO2
• Anharmonic thermodynamics redefines metastability and parent phases in ferroelectric HfO2
• Resistive switching in HfO2-x/La0.67Sr0.33MnO3 heterostructure: An intriguing case of low H-field susceptibility of an E-field controlled active interface
• 2022 Roadmap on Neuromorphic Computing and Engineering
• Control of domain states in rhombohedral PZT films via misfit strains and surface charges