Interlayer-Confined Molecular Assembly Enables a Family of Two-Dimensional Room-Temperature Ferromagnets

Area of Science:

• Materials Science
• Condensed Matter Physics
• Chemistry

Background:

• Developing two-dimensional (2D) molecular ferromagnets with robust room-temperature magnetism is challenging due to weak intermolecular interactions and structural instability.
• Existing methods struggle to achieve stable, long-range magnetic order at ambient temperatures in 2D molecular systems.

Purpose of the Study:

• To present a novel interlayer-confined molecular assembly strategy for creating 2D room-temperature molecular ferromagnets.
• To demonstrate the efficacy of van der Waals (vdW) hosts in controlling molecular orientation and enhancing spin alignment.
• To establish a generalizable approach for engineering 2D spintronic materials.

Main Methods:

• Utilizing a van der Waals (vdW) host material, specifically metallic TaS2, for intercalation.
• Employing cobaltocene as the molecular component to be confined within the vdW host.
• Investigating the effects of interlayer confinement on molecular assembly, spin alignment, and magnetic properties.

Main Results:

• Successfully constructed a family of 2D room-temperature molecular ferromagnets within metallic vdW hosts.
• Achieved precise molecular orientation control and enhanced spin alignment via vdW confinement.
• Observed long-range ferromagnetic order above 300 K, mediated by strong organic-inorganic interfacial coupling and itinerant-electron exchange.
• Demonstrated a notable negative magnetoresistance of -5.7% at 300 K.

Conclusions:

• The interlayer-confined molecular assembly strategy is effective for creating stable 2D room-temperature molecular ferromagnets.
• This approach offers a general method for molecularly engineering 2D spintronic materials by functionalizing magnetic small molecules.
• The findings highlight the potential of confined molecular assembly in advancing the field of 2D magnetism and spintronics.