Image of the Month

March 2010

Surface Potential Map of Graphene/SrTiO3

institution

Microscope:
RHK Technology UHV 7500 AFM/STM

Kelvin Probe Measurement on graphene exfoliated on SrTiO3 (Strontium titanate) obtained in non-contact AFM mode using a frequency shift of -5 Hz. The graphene was irradiated with Xenon 23+ ions under grazing incidence of 6°. On monolayer the impact of the ions lead to characteristic folding. In Bias-Image the exposed underlying substrate in this area can be clearly seen. Also the monolayer shows lower surface potential difference to SrTiO3 than few monolayers. EFM-Cantilever (Pt coated) from Budget Sensors with resonance frequency of 260 KHz (ElectriTap300-G). The cantilever oscillation amplitude is 22 nm and the data was obtained at room temperature.

Controls:
RHK Technology SPM 1000 Control System featuring XPMPro, PLLPro AFM Control System, and PMC100.

Contributors:
Benedict Kleine Bußmann, Oliver Ochedowski, Marika Schleberger AG Schleberger, University Duisburg-Essen