Dresden 2017 – wissenschaftliches Programm

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

MM: Fachverband Metall- und Materialphysik

MM 11: Biomaterials

MM 11.7: Vortrag

Montag, 20. März 2017, 13:15–13:30, IFW D

Surface, interface and bulk sensitive x-ray absorption spectroscopy probed by total electron yield in liquid cell — •Daniela Schön1,2, Jie Xiao1, Ronny Golnak1, Marc F. Tesch1, and Emad F. Aziz1,21Institute of Methods for Material Development, Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Strasse 15, 12489 Berlin, Germany — 2Freie Univeristät Berlin, Department of Physics, Arnimallee 14, 14195 Berlin, Germany

Total electron yield (TEY) is often adopted as a probing method for x-ray absorption spectroscopy (XAS). One electrode connecting to sample surface and measuring sample drain current is a common practice to obtain TEY-XA spectra, which makes the TEY method surface sensitive, owing to the short mean-free-path of photoelectrons. In this study, we demonstrate that the interface and bulk sensitive XAS can be individually probed by TEY as well when two electrodes are connected to the front and back sides of a liquid cell. The interfacial dipole layer is argued to be the key factor that separates the x-ray excited electron-hole pairs at interface and generates the resulting electric current which is eventually detected by ammeter as the TEY signal. The mobility and long-distance transportability of positive ions in liquid provides an indispensable assistance to realize the current flow in the liquid bulk. In the two-electrode connection scheme, the acquired current signal produces intensity peaks and dips for the interface and bulk species, respectively, upon the resonant excitations at their corresponding absorption edges.

100% | Mobil-Ansicht | English Version | Kontakt/Impressum/Datenschutz
DPG-Physik > DPG-Verhandlungen > 2017 > Dresden