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O: Fachverband Oberflächenphysik

O 81: Oxides and Insulator Surfaces I

O 81.4: Vortrag

Donnerstag, 10. März 2016, 11:30–11:45, H4

Decomposition of the model perovskite SrTiO₃ under electrochemical stress — •Christian Rodenbücher, Gustav Bihlmayer, Paul Meuffels, Rainer Waser, and Kristof Szot — Peter-Grünberg-Institut, Forschungszentrum Jülich, 52425 Jülich

Transition metal oxides are the key materials for future energy-efficient electronics in particular for logic and memory devices based on the resistive switching effect. Since the switching effect is related to a local reaction of the oxide to an external gradient of the electrical and chemical potential, we investigate the influence of electrochemical stress on the prototype perovskite SrTiO₃. We demonstrate that upon application of a DC voltage under UHV conditions, the surface region of alkaline earth titanates transforms into lower binary oxides with nanoporous structure. By means of IRT, XPS, EDX, HR-TEM, and LC-AFM we present that this transformation takes place at relatively low temperatures and is related to a fundamental macroscopic decomposition of the oxide changing the physical properties of the surface region up to depths of several tens of micrometers. Our results demonstrate that in ternary oxides phase transformations can be induced by gradients of the electrochemical potential using a technologically simple method, which not only opens up a new way for tailoring micro layers of functional transition metal oxides with bespoke properties for optical, electronic and chemical applications but also demonstrates the mutability of metal oxides under electrical stress being relevant for the understanding of the electroforming and switching process in novel memristive devices.