Enhanced thermal stability of zinc-based titanate (dielectric) ceramics prepared by the modified sol-gel route

A multi-component substitution of Co and Ni was incorporated into ZnTiO3 to form pure hexagonal Zn1-x(Co1/2Ni1/2)xTiO(3) (x = 0,0.8,0.9,1.0) dielectric ceramic powders by a modified sol-gel route, following heat treatments at 600 degrees C for 3 h and at 800 degrees C for 6 h. Differential scanning calorimetry measurements revealed that the order of increasing thermal stability of solid solution compound Zn1-x(Co1/2Ni1/2)(x)TiO3 was ZnTiO3 (945 degrees C), Zn0.1Ni0.9TiO3 (1346 degrees C), Zn-0.1(Co1/2Ni1/2)(0.9)TiO3 (1390 degrees C), and Zn0.1Co0.9TiO3 (> 1400 degrees C). Both the dielectric constant and loss tangent reached a maximum at x = 0.8 and then decreased with solubility, x, and measurement frequency.