Berlin 2008 – wissenschaftliches Programm
SYNF 1.11: Vortrag
Dienstag, 26. Februar 2008, 13:00–13:15, A 151
Resistive memory switching in perovskite-derivative single crystals — •P. Müller1, F. Chowdhury1, V. Dremov1, Y. Koval1, F. Lichtenberg2, S. Müller3, D. Schmeißer3, and R. Pentcheva4 — 1Institut für Physik der Kondensierten Materie, Universität Erlangen-Nürnberg — 2Experimentalphysik VI, Universität Augsburg — 3Lehrstuhl Angewandte Physik-Sensorik, BTU Cottbus — 4Department of Earth and Environmental Sciences, LMU München
We investigated several layered perovskite derivatives of the family AnBnO3n+2, such as LaTiO3.41, CaNbO3.41 and SrNbO3.41, which can be considered as a stacking of blocks consisting of 5 perovskite layers. Electric transport across these layers takes place via intrinsic tunnelling. Mesa devices with a cross-sectional area of 50 to 200 µm2 and a height between 30 and 500 nm were fabricated by electron-beam lithography and ion-beam etching. Both dc I-V characteristics and pulsed current injection have shown switching between different resistive states in these materials. The resistive states have long-term stability, which makes them interesting for memory applications. The transport experiments suggest that switching and resistive memory are controlled by trapping and release of charge carriers. Furthermore, photoelectron and NEXAFS spectroscopy of cleaved LaTiO3.41 surfaces have been performed. The results are compared to recent correlated band theory (LDA+U) calculations.