Magnetic moment preservation and emergent Kondo resonance of Co-phthalocyanine on semimetallic Sb(111)

TL;DR

This study demonstrates that Co-phthalocyanine molecules retain their magnetic moments on semimetallic Sb(111) surfaces, exhibiting Kondo resonance, which is promising for high-density magnetic memory applications.

Contribution

It reveals that semimetallic Sb(111) preserves molecular spins and induces Kondo resonance, providing insights into interfacial coupling and potential for molecular spintronics.

Findings

Magnetic moments are preserved on Sb(111) surfaces.

Emergent Kondo resonance indicates strong spin-electron interactions.

Potential for ultra-high density magnetic memory devices.

Abstract

Magnetic molecules on surfaces have been widely investigated to reveal delicate interfacial couplings and for potential technological applications. In these endeavors, one prevailing challenge is how to preserve or recover the molecular spins, especially on highly metallic substrates that can readily quench the magnetic moments of the ad-molecules. Here we use scanning tunneling microscopy/spectroscopy to exploit the semimetallic nature of antimony and observe, surprisingly yet pleasantly, that the spin of Co-phthalocyanine is well preserved on Sb(111), as unambiguously evidenced by the emergent strong Kondo resonance across the molecule. Our first-principles calculations further confirm that the optimal density of states near the Fermi level of the semimetal is a decisive factor, weakening the overall interfacial coupling, while still ensuring sufficiently effective electron-spin scattering in the many-body system. Beyond isolated ad-molecules, we discover that each of the magnetic moments in a molecular dimer or a densely packed island is distinctly preserved as well, rendering such molecular magnets immense potentials for ultra-high density memory devices.