Dresden 2017 – wissenschaftliches Programm
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MI: Fachverband Mikrosonden
MI 10: Positron Annihilation Spectroscopy (PALS)
MI 10.1: Vortrag
Donnerstag, 23. März 2017, 12:00–12:15, MER 02
Positron Annihilation Spectroscopy for Materials Science — •Andreas Wagner1, Wolfgang Anwand1, Reinhard Krause-Rehberg2, Maciej Oskar Liedke1, Kay Potzger1, and Thu Trang Trinh1,3 — 1Helmholtz-Zentrum Dresden-Rossendorf — 2Martin-Luther-Universität Halle — 3Technische Universität Dresden, Germany
Positron annihilation lifetime spectroscopy serves as a tool for studies of open-volume defects in solid materials such as vacancies, vacancy agglomerates, dislocations, pores and voids. The intense mono-energetic positron beam MePS installed at the superconducting electron accelerator ELBE allows for depth-dependent positron lifetime measurements and Doppler-broadening spectroscopy of thin films. Offline experiments using a radioisotope-based beam called SPONSOR complement those investigations. Here, in-situ modifications of the samples under study can be performed using a new setup called AIDA which allows for thin film growth by molecular beam epitaxy, ion-beam irradiation and sputtering in a temperature-controlled environment reaching from 50 K to 1200 K.
Selected experiments on open and closed porosity in thin films, positron chemistry in fluids, defect characterizations of semiconductors and metals will be presented.
The MePS facility has partly been funded by the Federal Ministry of Education and Research (BMBF) with the grant PosiAnalyse (05K2013). The initial AIDA system was funded by the Impulse- und Networking fund of the Helmholtz-Association (FKZ VH-VI-442 Memriox).