Some tungsten-bronze ferroelectrics were synthesized and characterized in the BaO-Sm2O3-TiO2-Nb2O5 system. Ba4Sm2Ti4Nb6O30 and Ba5SmTi3Nb7O30 had the tetragonal filled tungsten-bronze structure; while Ba3Sm3Ti5Nb5O30 consisted of the orthorhombic tungsten-bronze major phase and the BaTi4O9 secondary phase. The present dielectric ceramics exhibited relaxor behavior with the maximum temperatures around 185, 285 and 130degreesC for Ba3Sm3Ti5Nb5O30, Ba4Sm2Ti4Nb6O30 and Ba5SmTi3Nb7O30, respectively. Moreover, Ba3Sm3Ti5Nb5O30 exhibited a second possible phase transition around 93 degreesC. (C) 2003 Elsevier Science Ltd. All rights reserved. References: 18
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