| Abstract [eng] |
The tendency of miniaturization in electronics constantly produces the need of new materials — composites and, of course, new ways for use of well-known ones. One idea is to enclose the ferroelectric sample into matrices of porous materials, in order to obtain well characterized nanoparticles. The fundamental interest in this area is the desire to understand the new physics that occurs due to finite-size effects, surface forces and reduced dimensionality. This also applies for other non ferroelectric materials (polar liquids for ex.). The nature of confined phases, their structure, properties and their relation to the surface forces, pore dimensions and pore morphology and topology are of considerable interest, and are at present not well understood. The aim of this dissertation is to investigate the dynamics of water, methanol and various ferroelectrics (betaine phospfite, barium titanate, sodium nitrite), confined in different nanoporous materials, by means of dielectric spectroscopy in wide frequency and temperature ranges. Various mesoporous materials with different structure and pore size have been chosen to investigate peculiarities of melting-freezing and ferroelectric phase transition dynamics. The influence of pore size, structure and chemical composition of the hosting matrix on the dynamics of confined molecules is analyzed and ascertained. |
