Atomic-Resolution Mapping of Electric Fields and Strain across Single-Crystalline/Amorphous Interfaces

Area of Science:

• Materials Science
• Solid-State Physics
• Surface Chemistry

Background:

• Amorphous/crystalline interfaces are crucial in materials but poorly understood due to challenges in creating well-defined structures and probes.
• Structural distortion and charge redistribution at these interfaces significantly impact material properties.

Purpose of the Study:

• To construct atomically resolved single-crystalline/amorphous heterointerfaces.
• To map interfacial electric fields and strain using advanced microscopy techniques.
• To correlate atomic structure with interfacial electronic and mechanical properties.

Main Methods:

• Synthesis of transition metal oxytellurides to create model heterointerfaces.
• Scanning transmission electron microscopy (STEM) for atomic resolution imaging.
• Four-dimensional STEM (4D-STEM) to probe projected electric fields and strain.
• Electronic structure calculations to understand charge redistribution and electron behavior.

Main Results:

• Atomically resolvable single-crystalline/amorphous heterointerfaces were successfully constructed.
• 4D-STEM revealed locally enhanced and reorienting electrostatic fields at the interfaces.
• Electron accumulation in amorphous regions and depletion in crystalline regions indicate directional electron transfer.
• Nanometer-scale tensile and compressive strain were localized around the interfaces.
• Enhanced Ru 4d delocalization near the Fermi level was observed, suggesting suitability for electron-driven reactions.

Conclusions:

• The study provides a general route to elucidating structure-activity relationships at disordered-ordered interfaces.
• Spatially correlating atomic structure with built-in electric fields and lattice strain is now feasible.
• This approach offers insights into designing materials with tailored interfacial properties for various applications.