Kondo resonance of single Co atoms embedded in Cu(111) -: art. no. 201103

The Kondo resonance of single Co atoms embedded in a Cu matrix has been investigated with tunneling spectroscopy at T=8 K. Dilute magnetic alloys were prepared by homoepitaxial growth of Cu(111) films incorporating approximately 0.1% Co atoms as magnetic scattering centers. The Co impurities in the first layer of the Cu matrix show a characteristic, symmetric dip in the differential conductance around zero bias, indicating the presence of the many-body Abrikosov-Suhl resonance. The corresponding Kondo temperature is found to be T-K=405+/-35 K, which is much higher than previously reported values for Co adsorbate atoms.