Dresden 2017 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

MA: Fachverband Magnetismus

MA 67: Poster 4

MA 67.25: Poster

Freitag, 24. März 2017, 09:30–13:00, P2-OG3

Scanning Tunneling Microscopy in the Field Emission regime revisited — •Gabriele Bertolini, Lorenzo G. De Pietro, Oguzhan Gürlü, Urs Ramsperger, and Danilo Pescia — ETH Zurich, Zurich, Switzerland

In a Scanning Tunnelig Microscope retracting the tip from the sample by 5 to 100 nm and applying a suitable junction bias (-10 to -100 V tip bias) between them bring the tip-sample junction out of the tunnelling regime and the tip becomes a source of electrons due to field emission. In this regime the electrons arriving from the tip to the sample cause the generation of secondary electrons on the sample surface, which can escape from the tip-sample junction. Such electrons may be collected by several means and analysed. This technique is called as Field Emission Scanning Probe Microscopy. The strong dependence of the physical properties of the secondary electrons on the nature of the sample surface makes complementary information accessible. Besides the emitted and absorbed current maps and the z-piezo displacement images of the surface, chemical and magnetic contrast with nanometer scale resolution can be achieved on the same region that was scanned previously in the STM mode. We are currently aiming at detecting the spin polarization of the secondary electrons, for the purpose of magnetic imaging. In this presentation structural and electronic properties obtained on several pure-metallic and compound surfaces with previously not reported lateral resolution will be discussed.