Manipulating the magnetism of an adsorbed magnetic ion through its chemical bonding

We have demonstrated that the Kondo effect exerted by a magnetic ion depends on its chemical environment. A cobalt phthalocyanine molecule adsorbed on an Au(111) surface exhibited no Kondo effect. Cutting away eight hydrogen atoms from the molecule with voltage pulses from a scanning tunneling microscope tip allowed the four lobes of this molecule to chemically bond to the gold substrate. We found that the localized spin was recovered in this artificial molecular structure, and a clear Kondo resonance was observed near the Fermi surface.