Berlin 2008 – scientific programme

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O: Fachverband Oberflächenphysik

O 88: Metallic Nanostructures II (on Semiconductors)

O 88.7: Talk

Friday, February 29, 2008, 11:00–11:15, MA 005

Optical properties of single Mg particles on MgO thin films — •Philipp Myrach, Hadj Mohamed Benia, Niklas Nilius, and Hans-Joachim Freund — Fritz-Haber-Institut, Berlin, Germany

Light emission spectroscopy with an STM is employed to study the optical properties of single Mg particles grown on 5-10 ML thick MgO films on Mo(001). The particles exhibit distinct rectangular shapes with edges that align with the close-packed O rows of the oxide support. Luminescence spectra taken in the field emission regime (U>40 V) reveal a photon peak at 550 nm in addition to the well-known exciton emission of bare MgO at 400 nm. A similar emission peak is detected in the tunneling mode (U<10 V) for individual particles. The emission is assigned to a plasmon excitation in the Mg deposits. The high spatial resolution of the method allows also mapping of the emission intensity within one particle, thus providing information on the symmetry of the underlying optical mode.