%0 Journal Article
%T Nanostructured Ceramics of Potassium Sodium Bismuth Titanate: Hydrothermal Synthesis and Piezoelectric Response at Morphotropic Phase Boundary
%A Nissamuddeen Kunnath
%A Jacob Philip
%J New Journal of Glass and Ceramics
%P 1-14
%@ 2161-7562
%D 2019
%I Scientific Research Publishing
%R 10.4236/njgc.2019.91001
%X Potassium Sodium Bismuth Titanate (KNBT) ceramics, with the general formula (1<span style=\"font-family:Verdana;\"> </span><span style=\"font-family:Verdana;\">- </span><i><span style=\"font-family:Verdana;\">x</span></i><span style=\"font-family:;\" \"=\"\"><span style=\"font-family:Verdana;\">)K</span><sub><span style=\"font-family:Verdana;\">0.5</span></sub><span style=\"font-family:Verdana;\">Bi</span><sub><span style=\"font-family:Verdana;\">0.5</span></sub><span style=\"font-family:Verdana;\">TiO</span><sub><span style=\"font-family:Verdana;\">3</span></sub><i><span style=\"font-family:Verdana;\"> </span></i></span><span style=\"font-family:Verdana;\">-</span><i><span style=\"font-family:Verdana;\">x</span></i><span style=\"font-family:;\" \"=\"\"><span style=\"font-family:Verdana;\">Na</span><sub><span style=\"font-family:Verdana;\">0.5</span></sub><span style=\"font-family:Verdana;\">Bi</span><sub><span style=\"font-family:Verdana;\">0.5</span></sub><span style=\"font-family:Verdana;\">TiO</span><sub><span style=\"font-family:Verdana;\">3</span></sub><span style=\"font-family:Verdana;\">, have been synthesized following hydrothermal route, starting with solid solutions of pure perovskite</span></span><span style=\"font-family:Verdana;\"> </span><span style=\"font-family:Verdana;\">nanoceramics of KBT and NBT in desired stoichiometric weight ratios, followed by sintering between 850<span style=\"white-space:nowrap;\">กใ</span>C and 1000<span style=\"white-space:nowrap;\">กใ</span>C for few hours. Pure KNBT nanoceramics with perovskite structure, having mean particle size around 30 nm, could be obtained. Morphology of the samples is found to depend strongly on composition. A change of composition results in a phase change, as evident from X-ray structure analysis. This phase change is a result of rhombohedral to tetragonal morphotropic phase boundary</span><span style=\"font-family:;\" \"=\"\"><span style=\"font-family:Verdana;\"> (MPB) in the sample with </span><i><span style=\"font-family:Verdana;\">x</span></i><span style=\"font-family:Verdana;\"> around 0.80. Composition dependent occurrence of MPB leads to formation of needle like structures with micrometer length scales. These are typical of tetragonal lamellar structures, suggesting partial induction of tetragonal polar order from rhombohedral structure at MPB. Dielectric and piezoelectric properties, such as dielectric constant and loss, piezoelectric coefficients and figures of merit, exhibit threshold maxima in their values at the composition corresponding to MPB. These values reported for
%K Perovskite Nanoceramics
%K Morphotropic Phase Boundary (MPB)
%K Piezoceramic
%U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=89308