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DF: Fachverband Dielektrische Festkörper

DF 8: Dielectric and Ferroelectric Thin Films and Nanostructures II

DF 8.4: Talk

Wednesday, March 28, 2007, 15:50–16:10, H11

NMR Spectroscopy for Study of Size Effects in BaTiO3 fine particles and of Materials Embedded in Mesoporous Materials — P. Sedykh¹, E. V. Charnaya², G. Klotzsche¹, and •D. Michel¹ — ¹University of Leipzig, Institute for Experimental Physics II, Linnéstrasse 5, 04103 Leipzig — ²Institute of Physics, St.Petersburg State University, St.Petersburg, 198904, Russia

Studies of size effects on ferroelectric properties have obtained a great impetus in recent years. Ultrafine BaTiO3 powders are prepared from a monomeric metallo-organic precursor through combined-solid state polymerization and pyrolysis (CPP) [1-3] with particle size (dm) in the range between 15 nm and 250 nm. The properties of BaTiO3 powders were characterized by various methods (FT-Raman, XRD, SEM and 137Ba NMR). Critical particle diameters for the disappearance of ferroelectricity are estimated. A structural model for a nanograin is derived. Moreover, we study the behavior of BaTiO3 and other ferroelectrics embedded into mesoporous MCM 41 materials and in porous glasses. An overview about our recent work will be given.

[1] H. J. Gläsel, E. Hartmann, R. Böttcher, C. Klimm, B. Milsch, D. Michel, H.-C. Semmel-hack, J. Hormes, J. Materials Science 34(1999)1-5 [2] E. Erdem, R. Böttcher, H.-C. Semmelhack, H.-J. Gläsel, E. Hartmann, D. Hirsch, J. Mater. Sci. 38 (2003) 3211-3217 [3] E. Erdem, PhD Thesis, University of Leipzig, 2006