Sub-Ångstrom-scale structural variations in high-entropy oxides

Area of Science:

• Materials Science
• Solid-State Chemistry
• Nanotechnology

Background:

• High-entropy oxides (HEOs) are advanced materials with potential applications owing to their exceptional physical and chemical properties.
• Understanding the atomic-scale structure-property correlations in HEOs is crucial but remains insufficiently explored compared to high-entropy alloys.

Purpose of the Study:

• To investigate and quantify atomic-scale structural variations and lattice distortions in representative high-entropy oxides.
• To establish a foundation for correlating local structural features with the functionalities of HEOs.

Main Methods:

• Utilized advanced aberration-corrected scanning transmission electron microscopy (STEM) techniques.
• Examined four distinct HEOs with pyrochlore, spinel, perovskite, and rock-salt structures.
• Quantified sub-ångstrom-scale structure variations and local lattice distortions.

Main Results:

• Successfully visualized and quantified local structural variations at the sub-ångstrom scale in various HEOs.
• Demonstrated the presence of significant lattice distortions within the HEO structures.
• Provided direct experimental evidence of atomic-scale structural heterogeneity.

Conclusions:

• The study provides a valuable methodology for investigating local fluctuating structures in high-entropy oxides.
• These findings pave the way for deeper understanding and tailored design of HEOs based on their intricate atomic structures.