Discontinuous domain wall motion in the relaxor ferroelectricD. C. Lupascu1, T. Granzow1, 2 and Th. Woike2
1 Institute of Materials Science, Darmstadt University of Technology Petersenstr. 23, 64287 Darmstadt, Germany (http://www.tu-Darmstadt.de/fb/ms/fg/na/)
2 Institute of Mineralogy & Geochemistry, University of Cologne Zülpicherstrasse 49b, 50674 Köln, Germany
received 8 June 2004; accepted 7 October 2004
published online 29 October 2004
The relaxor ferroelectric strontium-barium-niobate is characterized by internal random electric fields at the origin of its relaxor behavior. The electric poling cycle induces an irreversible transition into a ferroelectric state accompanied by a large flow of mobile charges. Bipolar fields applied in the poled state yield no acoustic emissions for half-cycles in poling direction. In contrast, discontinuous domain wall movement is observed under reverse fields. The data cannot be explained by homogeneous clouds or gradients of space charge, but necessitate charge cluster formation to a certain degree. The irreversibility of the poling process necessitates charge carrier activation by large electric fields.
77.80.Dj - Domain structure; hysteresis.
77.84.Dy - Niobates, titanates, tantalates, PZT ceramics, etc.
43.40.Le - Techniques for nondestructive evaluation and monitoring, acoustic emission.
© EDP Sciences 2004