Recent progress on defect-engineering in ferroelectric HfO₂: The next step forward via multiscale structural...

Area of Science:

• Materials Science
• Solid State Physics
• Nanotechnology

Background:

• Unconventional scale-free ferroelectricity in HfO2-based fluorite thin films is crucial for low-power logic and nonvolatile memories.
• The ferroelectric properties of HfO2 are intrinsically linked to the metastable orthorhombic Pca21 phase.
• Defect-doping and solid solutions offer pathways to enhance and stabilize ferroelectricity through isovalent or aliovalent engineering.

Purpose of the Study:

• To review recent advancements in defect-engineered HfO2-based ferroelectrics.
• To summarize defect-lattice correlations, phase transition kinetics, and oxygen vacancy behavior.
• To discuss future prospects and challenges in optimizing ferroelectric properties via defect engineering.

Main Methods:

• Review of defect-doping strategies, including mono-ionic and mixed ion-doping.
• Analysis of defect-lattice correlations and their impact on phase transition kinetics.
• Summary of thin film preparation techniques and ion bombardment doping.

Main Results:

• Defect engineering, through various doping methods, has shown significant promise in enhancing and stabilizing ferroelectricity in HfO2-based materials.
• Understanding defect-lattice interactions and oxygen vacancy dynamics is key to controlling ferroelectric properties.
• Progress has been made in thin film preparation and ion bombardment doping for defect introduction.

Conclusions:

• Defect engineering is a powerful approach for optimizing ferroelectric properties in HfO2-based fluorite thin films.
• A multiscale structural optimization approach is suggested for further advancements.
• This review provides insights into the state-of-the-art and future directions for defect-engineered ferroelectrics.