Dresden 2011 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 2: Topical Session TEM I
MM 2.2: Topical Talk
Montag, 14. März 2011, 11:30–12:00, IFW A
In-situ TEM as a nanolab for studying electrical and electrochemical transport mechanisms in perovskites — •Christian Jooss1, Jonas Norpoth1, Stephanie Raabe1, Malte Scherff1, Joerg Hoffmann1, James Ciston2, Dong Su2, Lijun Wu2, and Yimei Zhu2 — 1Institute of Materials Physics, University of Goettingen, Germany — 2Brookhaven National Laboratory, Upton NY, USA
Perovskite oxide materials with strong electronic or electron-lattice correlations exhibit a rich variety of properties ranging from colossal resistance effects over remanent resistance switching to multi-electron transfer in catalytic reactions. Intrinsic inhomogeneities such as electronic phase separation on the nanoscale and extreme sensitivity to defect structure make atomic resolution studies of properties and behavior in external fields highly desirable, in order to understand underlying mechanisms. In this talk, we will show through two examples, the opportunities of in-situ TEM for a detailed understanding of electrical transport properties in doped manganites. In one example, a piezo-controlled STM tip (Nanofactory) has been used to electrically stimulate a hole-doped manganites and metal-manganites heterostructures. The induced resistance change was correlated to the locally induced structural and electronic changes. In the second example, in-situ studies of water splitting using CaMnO3 based catalysts have been performed in a FEI Titan microscope with an environmental chamber. Catalytic activity was observed at specific crystalline sites and related changes in the oxidation state of the Mn cations during the reaction were recorded via Electron Energy Loss Spectroscopy.