Procesy relaksacyjne zachodzące w manganianie bizmutu stanowiącym matrycę dla PbTiO₃ lub domieszkę w ceramice Pb(Zr0.70Ti0.30)O₃

Abstract

Doctoral Thesis show the electrical properties in relation to degree of structural heterogeneity, performed by using dielectric spectroscopy and scanning electron microscopy. The results obtained for the following materials are shown in Thesis: • bismuth manganite B-M-O and/or BM • lead zirconate titanate PZT • (1-x)PZT-xBM, where x = 0.00, 0.01, 0.02, 0.03, 0.04, 0.05, 0.055, 0.11, 0.15, 0.22 • (1-x)B-M-O-xPTO, where x = 0.04, 0.12, 0.24 • epoxy glue/B-M-O composite • epoxy glue/(1-x)PZT-xBM composite, where x = 0.00, 0.01, 0.11, 0.22. The Doctoral Thesis include motivation, literature review of the phenomena and models related to subject of studies, description of technology applied for production of the samples, and description of the apparatus set-up. Next part shows results and discussion. Properties of the reference bismuth manganite and the influence of the BM doping on dielectric permittivity, on relaxation properties, on induced relaxor state, on piezoelectric properties and on electrical conductivity of the PZT-BM ceramics. It was showed that BM increased crystal lattice disorder, induced one of the relaxation processes, modified piezoelectric features. The influence of PTO addition on B-MO properties was studied. It occurred that the PTO powders increased electrical conductivity of the B-M-O-PTO ceramics that covers the relaxation processes. It was shown that reduction of electrical conductivity was possible in new composite materials epoxy glue/B-M-O and epoxy glue/PZT-BM. The most important achievements of Doctoral Thesis were: (1) determination of the phase diagrams of PZT-BM for low and high concentrations of BM and (2) preparation of the composite epoxy glue/B-M-O and epoxy glue/PZT-BM materials, which exhibited reduced value of electrical conductivity in comparison to the reference ceramics. Moreover the Doctoral Thesis include results and references.