PROCESSING AND PROPERTIES OF NANOCRYSTALLINE Pb(Sc_(0.5)Ta_(0.5))O_3, Pb(Sc_(0.5)Nb_(0.5))O_3, Pb(Mg_(1/3)Nb_(2/3))O_3 and Pb_(0.76)Ca_(0.24)TiO_3 FILMS AND FERROELECTRIC/RELAXOR SUPERLATTICES

摘要

Thin films of relaxor materials, namely Pb(Sc_(0.5)Ta_(0.5))O_3, (PST), Pb(Sc_(0.5)Nb_(0.5))O_3, (PSN) and Pb(Mg_(1/3)Nb_(2/3))O_3 (PMN), and Pb_(0.76)Ca_(0.24)TiO_3 (PTC), which is a classical ferroelectric as bulk material, have been produced to examine whether nanocrystalline relaxor materials show influences in their properties if their grain size is reduced to dimensions known from their nanodomains and to investigate effects in a superlattice of nanocrystalline ferroelectric and relaxor films. At first amorphous films of the different materials were deposited onto a Ti/Pt coated Silicon (100) wafer by reactive rf-sputtering. Different grain sizes could be prepared by a controlled annealing process. The increasing size of the crystallites, the crystal structure and the pyrochlore-perovskite transformation have been investigated by profile analysis of the XRD spectra. Temperature and frequency dependent dielectric measurements show typical relaxor properties in the single layers and the existence of two maxima in the superlattices, so EC/ZFC curves were recorded to clarify their nature.