MnBr 2 ${\rm MnBr}_2$ on the Graphene on Ir(110) Substrate: Growth, Structure, and Super-Moiré

Area of Science:

• Materials Science
• Surface Science
• Condensed Matter Physics

Background:

• Graphene on Ir(110) serves as a substrate for novel material growth.
• Understanding epitaxial relationships is crucial for heterostructure development.
• Magnetic insulators on 2D materials offer unique electronic and magnetic properties.

Purpose of the Study:

• To characterize the growth and structure of single-layer MnBr2 on graphene/Ir(110).
• To investigate the formation of super-moiré patterns in this three-lattice system.
• To elucidate the origin of the virtual moiré and its relation to substrate properties.

Main Methods:

• Low-energy electron diffraction (LEED)
• Scanning tunneling microscopy (STM) and spectroscopy (STS)
• Ab initio calculations and Fourier analysis

Main Results:

• MnBr2 growth morphology is temperature-dependent, ranging from fractal to compact dendritic-skeletal islands.
• A unique super-moiré pattern is observed due to the virtual moiré between MnBr2 and the Ir(110) lattice.
• The virtual moiré originates from the inhomogeneous binding of graphene to the Ir(110) substrate.

Conclusions:

• Single-layer MnBr2 on graphene/Ir(110) forms a complex super-moiré structure.
• The study reveals insights into surface diffusion and electronic properties.
• This system provides a unique platform for exploring emergent phenomena in van der Waals heterostructures.