Identifying Strain Stacking Boundaries between Multiphase Domains in Atomically Thin Two-Dimensional Magnets

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Stacking engineering of van der Waals materials is crucial for tuning properties like magnetism.
• Atomically thin chromium trihalides (CrX3) are key systems for studying 2D magnetism.
• Controlling stacking sequences in CrX3 is essential for tailoring magnetic characteristics.

Purpose of the Study:

• To investigate stacking sequences and sliding mechanisms in atomically thin CrX3.
• To understand the relationship between stacking structure and magnetic properties.
• To identify strategies for controlling stacking in CrX3 for device applications.

Main Methods:

• Advanced electron microscopy to identify stacking sequences in CrX3 (X = Cl, Br) down to bilayer thickness.
• Analysis of lateral domain sizes and transitions at stacking boundaries.
• Comparison with density functional theory calculations and strain field analysis.

Main Results:

• Multiple stacking sequences were identified in thin CrX3, correlating with bulk phases.
• Nanometer-scale transitions and interactions at stacking boundaries were observed.
• A universally preferred sliding direction was discovered, consistent with theoretical predictions.

Conclusions:

• Local stacking structures significantly impact averaged magnetic properties of CrX3.
• The identified preferred sliding direction offers a method to control stacking during fabrication.
• This work provides a pathway for engineering magnetic properties in 2D van der Waals materials.