Abstract
PbMgNb(OAc) x (OR) y precursor was prepared from Pb and Mg acetates by dissolution in acetic acid (AcOH) and by mixing with Nb-ethyleneglycol-tartarate (Pechini) complex. The sol was formed after hydrolysis by various addition of water at 80°C and it was transformed by polycondensation to PMN two-phase gel. By the calcination of gel at the temperature of 500°C for 2 hours, the two-phase system was created with perovskite and undesirable pyrochlore phases. The content of the Pb(Mg 1/3 Nb 2/3 )O 3 perovskite phase in PMN calcinates was increased from 0 to 60 vol.% by decreasing of water addition as it results from DTA, TG analysis, IR spectroscopy and XRD analysis. The Pb 1.83 (Mg 0.29 Nb 1.71 )O 6.39 pure pyrochlore phase was found in the calcinate prepared from gel with higher addition of water and hydrolyzing factor (h) equals 43. The content of perovskite phase in calcinate was approximately 60 vol.% at h = 21 and without water addition to sol. The partial decomposition of the pyrochlore phase with transformation into the perovskite phase (the maximal volume fraction of perovskite phase ∼ 70 vol.%) was observed above the sintering temperature of 1100°C. Densities of PMN ceramics sintered at 1200°C decreased with the content of py phase in PMN calcinates. The maximal value of ϵ r = 4200 (at 1 kHz) was found in the ceramic sample with the highest content of perovskite phase and density.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
