Microwave dielectric and elastic properties of glass-added Ba6-3xR8+2xTi18O54 (x=2/3)

Abstract

Microwave dielectric properties of Ba6-3xSm8+2xTi18O54(x=2/3) [BST] ceramics with the addition of 0-3wt.% of various glasses have been studied. It has been found that the addition of 0.5wt.% of the glasses decreases the sintering temperature by about 150 degrees C. In general, addition of 0.5wt.% of Zn, Mg and Pb-based glasses deteriorate the quality factor, whereas aluminum and barium borosilicates do not decrease it considerably. The quality factor and dielectric constant decrease with increasing amount of glass. The temperature coefficient of resonant frequency shifts towards positive or negative depending on the composition of the glass. A glass-ceramic composite with a dielectric constant 64, Q x f nearly 8500 GHz and near to zero tau(f) could be obtained at a sintering temperature of 1175 degrees C when 3-4wt.% Al2O3-B2O3-SiO2 glass was added to BST ceramic. The Young's modulus decreases with increasing amount of glass, irrespective of the composition of glass. (