The effect of glass addition on the dielectric properties of barium strontium titanate

Ba0.7Sr0.3TiO3 (BST) ceramics were prepared by the conventional solid state ceramic route. Different weight percentages of twelve different glasses were added to the calcined BST ceramics and sintered. The structure and microstructure of the sintered materials were investigated by X-ray diffraction and Scanning Electron Microscopic techniques. The low frequency dielectric properties of the glass-ceramic composites were measured using LCR meter. Some of the glasses improved the dielectric properties and considerably lowered the sintering temperature. The glasses were prepared and characterized under identical conditions. Among the different glasses, 1.5 wt% addition of 71ZnO-29B(2)O(3) lowered the sintering temperature of BST to 975 degrees C with a dielectric loss of 9 x 10(-3) and dielectric constant of 875 at 1 MHz. The curie temperature of BST ceramics was found to shift towards lower temperature with glass addition.