Large Magnetic Anisotropy of a Single Atomic Spin Embedded in a Surface Molecular Network
Cyrus F. Hirjibehedin,1
Chiung-Yuan Lin,1,2
Alexander F. Otte,1,3
Markus Ternes,1,4
Christopher P. Lutz,1
Barbara A. Jones,1
Andreas J. Heinrich1
Magnetic anisotropy allows magnets to maintain their direction of magnetization over time. Using a scanning tunneling microscope to observe spin excitations, we determined the orientation and strength of the anisotropies of individual iron and manganese atoms on a thin layer of copper nitride. The relative intensities of the inelastic tunneling processes are consistent with dipolar interactions, as seen for inelastic neutron scattering. First-principles calculations indicate that the magnetic atoms become incorporated into a polar covalent surface molecular network in the copper nitride. These structures, which provide atom-by-atom accessibility via local probes, have the potential for engineering anisotropies large enough to produce stable magnetization at low temperatures for a single atomic spin.
1 IBM Research Division, Almaden Research Center, San Jose, CA 95120, USA.
2 Center for Probing the Nanoscale, Stanford University, Stanford, CA 94309, USA.
3 Kamerlingh Onnes Laboratorium, Universiteit Leiden, 2300 RA Leiden, Netherlands.
4 Institut de Physique des Nanostructures, École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland.
To whom correspondence should be addressed. E-mail: heinrich{at}almaden.ibm.com
