Mgbemere, Henry EkeneHenry EkeneMgbemereSchneider, Gerold A.Gerold A.SchneiderStegk, TobiasTobiasStegk2010-06-142010-06-142010Functional materials letters ; Vol. 3.2010, no.1, pp. 25-30627848672http://tubdok.tub.tuhh.de/handle/11420/810The effect of antimony substitution for niobium on potassium sodium niobate (KNN) ceramic was investigated with respect to the densification behaviour at different sintering temperatures, microstructure and electrical properties. Sb5+ was slightly added while simultaneously lowering the amount of Nb5+and in this study of the (K0.5Na0.5)(Nb1-xSbx)O3 system, x content was varied from 0 to 14 mol.% Our results show that Sb5+ slightly increased the optimum sintering temperature for KNN but above 8 mol %, its resistivity and piezoelectric properties decreased. As the amount of Sb5+ substituted is increased, the structure of the ceramic transformed from orthorhombic to pseudocubic which led to slight shrinkage in the unit cell volume. Microstructural examination revealed that above 10 mol %, a second phase (K2NaSb3O9) was formed which segregated mainly to the grain boundary while the quantitative EDX analysis showed that there was A-site vacancy due to loss of the alkali elements. The two phase transitions points, Curie temperature (TC) and the tetragonal to orthorhombic (TT-O) shifted to lower temperature with increasing Sb5+ content and above 10 mol %, the TT-O shifted to below room temperature. The dielectric loss slightly increases with increasing Sb5+ content up to 200°C. There was an improvement in the piezoelectric properties with ≤ 6 mol % Sb content while optimum properties were obtained with 4 mol % (KP = 0.46, Qm= 6.2, NP = 2296).enhttp://doku.b.tu-harburg.de/doku/lic_ohne_pod.phpblei frei piezokeramikkalium natrium niobatLead-free piezoelectricsceramicspotassium sodium niobateIngenieurwissenschaftenEngineering and allied operationsWorking Paper2010-06-14urn:nbn:de:101:1-20150526164710.15480/882.808Werkstoffe mit besonderen EigenschaftenWerkstoffprüfung, WerkstoffuntersuchungKeramische Werkstoffe, HartstoffePiezokeramik11420/81010.15480/882.808930768585Working Paper