Proximity-Driven Magnetic Coupling between an Open-Shell Nanographene and a Rare-Earth Surface Alloy

Area of Science:

• Materials Science
• Condensed Matter Physics
• Surface Science

Background:

• Open-shell nanographenes possess tunable spin ground states, crucial for spintronics.
• Characterization often uses weakly interacting substrates like noble metals.
• The impact of magnetic surfaces on nanographene magnetism is under-explored.

Purpose of the Study:

• Investigate the influence of the rare-earth alloy TbAu2 on the magnetic properties of phenalenyl ([2]triangulene, 2T).
• Explore the interaction between spin-1/2 nanographenes and magnetic surfaces.

Main Methods:

• Scanning tunneling spectroscopy (STS) measurements.
• Comparison of 2T on Au(111) versus 2T on TbAu2.
• Combined experimental and many-body model analysis.

Main Results:

• 2T on Au(111) shows a Kondo resonance.
• TbAu2 induces a significant ~20 mV splitting of the Kondo resonance in 2T.
• This splitting is attributed to proximity-induced interaction with TbAu2's ferromagnetic magnetization.
• The interaction is spatially modulated, following the TbAu2 surface superstructure periodicity.

Conclusions:

• TbAu2 is a viable platform for stabilizing and characterizing magnetic properties of spin-1/2 nanographenes.
• TbAu2 enables the study of interactions between π-magnetic materials and magnetic substrates.
• Proximity effects on magnetic surfaces offer new avenues for spintronic device development.