Colossal oxygen vacancy formation at a fluorite-bixbyite interface.

Area of Science:

• Materials Science
• Solid State Chemistry
• Nanotechnology

Background:

• Oxygen vacancies in complex oxides are crucial for information and energy applications.
• Existing methods for creating oxygen vacancies primarily focus on bulk materials.
• The potential of ionic interfaces for generating oxygen vacancies remains underexplored.

Purpose of the Study:

• To explore the use of ionic interfaces for creating oxygen vacancies.
• To design and investigate an oxide nanobrush architecture for high-density interfacial oxygen vacancies.
• To demonstrate the application of such interfaces in advanced electronic devices.

Main Methods:

• Fabrication of an oxide nanobrush architecture with a (111) heterointerface between fluorite CeO2 and bixbyite Y2O3.
• Utilizing local structure and chemical analyses.
• Performing theoretical calculations to understand defect formation and properties.

Main Results:

• A well-defined heterointerface between CeO2 and Y2O3 was created.
• Charge modulation between Y3+ and Ce4+ ions was observed due to valence mismatch.
• Spontaneous removal of over 10% of oxygen atoms occurred without lattice degradation.
• High-density interfacial oxygen vacancies were successfully generated.

Conclusions:

• The oxide nanobrush architecture effectively creates high-density interfacial oxygen vacancies.
• This platform enables precise control and transport of oxygen vacancies.
• The findings are critical for developing ionotronic and memristive devices for energy and neuromorphic computing.