Structure and dielectric properties of BaTi1-x(Sb0.5Nb0.5)xO3 ceramics

BaTi1-x(Sb0.5Nb0.5)(x)O-3 ceramics (0.01 <= x <= 0.3) were prepared by solid-state reaction method. The effect of co-substituting Ti4+ with Sb3+ and Nb5+ on its crystal structure, microstructure, and dielectric properties was studied. When 0.01 <= x <= 0.1, a single-phase barium titanate solid solution can be obtained; when 0.15 <= x <= 0.25, a small amount of unknown second phase was appeared; and when the composition (x) increases to 0.3, a large amount of unknown second phases are precipitated. The main crystal phase of BaTi1-x(Sb0.5Nb0.5)(x)O-3 ceramics has a change of tetragonal to cubic with the increase of x. As x increases from 0.1 to 0.25, the dielectric constant decreases from 1264 to 214, the dielectric loss decreases from 0.253% to 0.046% (1 MHz, 25 degrees C), the capacitance temperature coefficient changes from - 7897 to - 1657 ppm/ degrees C, and the insulation resistivity is greater than 10(12) omega cm. This means that BaTi1-x(Sb0.5Nb0.5)(x)O-3 (x = 0.1 similar to 0.25) ceramics can be suitable for temperature-compensated ceramic capacitors.