J. Phys. IV France 128 (2005) 81-85
Dielectric spectroscopy of BaTiO3 confined in MCM-41 mesoporous molecular sieve materialsM. Kinka1, J. Banys1, W. Böhlmann2, E. Bierwirth2, M. Hartmann3, D. Michel2, G. Völkel2 and A. Pöppl2
1 Faculty of Physics, Vilnius University, Sauletekio 9, 2040 Vilnius, Lithuania
2 University of Leipzig, Faculty of Physics and Geoscience, Linnéstr. 5, 04103 Leipzig, Germany
3 Department of Chemistry, Chemical Technology, University of Kaiserslautern, Erwin-Schrödinger-Str. 54, 67663 Kaiserslautern, Germany
Dielectric properties of Barium titanate particles, synthesized directly in the pores of MCM-41 materials, have been investigated in the frequency range from 20 Hz to 1 MHz for temperature interval from 100 K to 500 K. The pore diameters were 2.0 nm, 2.5 nm and 3.7 nm, and thus the synthesized particles size was already below the critical size of BaTiO3. The dielectric spectra of Barium titanate confined in these molecular sieves were compared with the results obtained from the investigation of pure MCM-41 materials. Obtained results confirmed successful incorporation of BaTiO3 into porous matrix but no phase transition from paraelectric to ferroelectric phase was observed due to the particle size being smaller than the critical size. Also the overall dielectric response of investigated materials is strongly influenced by adsorbed water molecules.
© EDP Sciences 2005