Temperature-independent permittivity of xSaTiO3-(1-x) (0.5Bi(Mg1/2Ti1/2)O3-0.5BiScO3) ceramics

xBaTiO(3)-(1-X)(0.5Bi(Mg1/2Ti1/2)O-3-0.5BiScO(3)) or xBT-(1-x)(0.5BMT-0.5BS) (x=0.45-0.60) ceramics were prepared by using the conventional mixed oxide method. Perovskite structure with pseudo-cubic symmetry was observed in all the compositions. Dielectric measurement results indicated that all the samples showed dielectric relaxation behavior. As the content BaTiO3 was decreased from 0.60 to 0.45, temperature coefficient of permittivity (TC epsilon) in the range of 200-400 degrees C was improved from -706 to -152 ppm/degrees C, while the permittivity at 400 degrees C was increased from 1208 to 1613. The temperature stability of permittivity was further improved by using 2 mol% Ba-deficiency. It was found that lattice parameter and grain size of the 2 mol% Ba-deficient ceramics were smaller than those of their corresponding stoichiometric (S) counterparts, with TC epsilon in the range of 200-400 degrees C to be improved noticeably. For example, TC epsilon of the Ba-deficiency sample with x=0.45 was -75 ppm/degrees C in the temperature range of 200-400 degrees C and the permittivity was 1567 at 400 degrees C. The results obtained in this work indicated that xBT-(1-x)(0.5BMT-0.5BS) ceramics are very promising candidates for high temperature capacitor applications. (C) 2016 Elsevier Ltd and Techna Group S.r.l. All rights reserved.