Spin excitations of individual magnetic dopants in an ionic thin film

Individual magnetic transition metal dopants in a solid host usually exhibit relatively small spin excitation energies of a few meV. Using scanning tunneling microscopy and inelastic electron tunneling spectroscopy (IETS) techniques, we have observed a high spin excitation energy around 36 meV for an individual Co substitutional dopant in ultrathin NaCl films. In contrast, the Cr dopant in the NaCl film shows much lower spin excitation energy around 2.5 meV. Electronic multiplet calculations combined with first-principles calculations confirm the spin excitation induced IETS, and quantitatively reveal the out-of-plane magnetic anisotropies for both Co and Cr. They also allow reproducing the experimentally observed redshift in the spin excitations of Co dimers and ascribe it to a charge and geometry redistribution.

Automated summary

Using scanning tunneling microscopy and inelastic electron tunneling spectroscopy, researchers have observed different spin excitation energies for individual Co and Cr dopants in ultrathin NaCl films. The spin excitation energy for Co dopants is relatively high at around 36 meV, while the spin excitation energy for Cr dopants is much lower at around 2.5 meV. Electronic multiplet calculations and first-principles calculations confirm the spin excitation induced IETS and quantitatively reveal the magnetic anisotropies for both Co and Cr.