Local magnetic properties of a monolayer of Mn12 single molecule magnets

The magnetic properties of a monolayer of Mn-12 single molecule magnets grafted onto a silicon (Si) substrate have been investigated using depth-controlled beta-detected nuclear magnetic resonance. A low-energy beam of spin-polarized radioactive Li-8 was used to probe the local static magnetic field distribution near the Mn-12 monolayer in the Si substrate. The resonance line width varies strongly as a function of implantation depth as a result of the magnetic dipolar fields generated by the Mn-12 electronic magnetic moments. The temperature dependence of the line width indicates that the magnetic properties of the Mn-12 moments in this low-dimensional configuration differ from bulk Mn-12.