Dresden 2017 – wissenschaftliches Programm
DS 46.6: Vortrag
Freitag, 24. März 2017, 10:45–11:00, CHE 89
Chemical Diffusion of Potassium Ions in thin film PrMnO3 — •Karl-Michael Weitzel1, Johannes Martin1, Melanie Gräf1, Thilo Kramer2, and Christian Jooss2 — 1Philipps-Universität Marburg — 2Universität Göttingen
The transport of potassium through praseodymium-manganese oxide (PrMnO3) has been investigated by means of the bombardment induced ion transport (BIIT) technique. To this end potassium ions are attached to the front side of a 250 nm thick sample of PrMnO3. Most of the potassium ions become neutralized at the surface of the PrMnO3. Part of the potassium ions diffuse through the PrMnO3. Ex situ analysis of the sample by time-of-flight secondary ion mass spectrometry (ToF-SIMS) reveals pronounced concentration profiles of the potassium indicative of chemical diffusion. Two distinctly different diffusion coefficients have been derived, i. one assigned to bulk diffusion and ii. another one assigned to diffusion along grain boundaries. The latter conclusion is supported by transmission electron microscopy of thin lamella cut out from the sample which reveals twin grain boundaries reaching through the entire sample.