Charge-transfer-induced nesting antiferromagnetism in 2D hydrogen-bonded organic frameworks

Area of Science:

• Materials Science
• Condensed Matter Physics
• Organic Chemistry

Background:

• Non-relativistic spin-split (NRSS) antiferromagnets (AFMs) are crucial for antiferromagnetic spintronics due to minimal spin dephasing and absence of stray magnetic fields.
• Γ-split AFMs, a subclass of NRSS AFMs, exhibit spin splitting at the Brillouin zone's Γ point, but their realization is limited to inorganic materials.
• Molecular frameworks offer tunable properties and diverse structures, presenting a promising avenue for novel AFMs.

Purpose of the Study:

• To explore the potential of 2D hydrogen-bonded organic frameworks (HOFs) for realizing Γ-split AFMs.
• To propose a new strategy for designing low-dimensional, molecule-based NRSS AFMs.

Main Methods:

• Utilizing density functional theory (DFT) calculations.
• Designing 2D HOFs by nesting honeycomb and Kagome lattices.
• Investigating charge transfer mechanisms between donor and acceptor molecules linked by hydrogen bonds.

Main Results:

• Five designed nesting HOFs were confirmed to be Γ-split AFMs.
• The ferromagnetic ordering within each sublattice arises from charge transfer between connected donor and acceptor molecules.
• The proposed 'nesting AFMs' feature separate ferromagnetic sublattices with opposite spin polarization.

Conclusions:

• 2D HOFs provide a viable platform for realizing molecule-based Γ-split AFMs.
• This work presents a practical strategy for designing novel low-dimensional NRSS AFMs for antiferromagnetic spintronics applications.
• The findings expand the scope of materials for advanced spintronic devices.