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DF: Fachverband Dielektrische Festkörper

DF 15: Thin Films and Nanostructures II

DF 15.3: Vortrag

Donnerstag, 26. März 2009, 11:20–11:40, WIL B321

Switching kinetics in epitaxial BiFeO₃ thin films with different orientations — •Daniel Pantel¹, Ying-Hao Chu², Ramamoorthy Ramesh³, and Marin Alexe¹ — ¹Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, D-06120 Halle (Saale), Germany — ²Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu, Taiwan 30010, R.O.C. — ³Department of Materials Science and Engineering, University of California, Berkeley, CA 94720, USA

Due to simultaneously ferroelectric and antiferromagnetic ordering at room temperature multiferroic BiFeO₃ (BFO) is a potential material for magnetoelectric devices. Furthermore, it is a Pb-free ferroelectric with high remnant polarization and therefore a promising candidate for environmental-friendly applications such as non-volatile memories. For all applications understanding of the detailed switching behavior in BFO is essential.

Large timescale (100 ns to 1 s) voltage pulse trains were used to examine the switching kinetics in BFO thin films with (001), (110) and (111) orientations as a function of applied voltage and time. The kinetics are analyzed in terms of Kolmogorov-Avrami-Ishibashi (KAI) theory and compared with standard systems such as epitaxial Pb(Zr_0.2Ti_0.8)O₃ (PZT) films. Likewise in fully c-oriented PZT films, BFO fits well the KAI-model in the high field region, whereas the low field region shows non-KAI kinetics comparable with PZT films with 90 ^∘ domain walls.