Dielectric properties of Mg-doped Ba0.6Sr0.4TiO3 ceramics prepared by using sol–gel derived powders

Structural and dielectric properties of yMgO–(1 − y)Ba0.60Sr0.40TiO3 (BST) (where y = 3, 5, 10, 20, 30 and 40 mol%) ceramics prepared by using sol–gel derived powders have been investigated. It is found that a careful control of the synthesis process enables producing a pure perovskite BST phase at a relatively low calcining temperature of 600 °C. Two phases, corresponding to BST and MgO phases, are clearly visible when MgO content up to 20 mol%. The influence of MgO additive on dielectric properties of BST ceramics can be classified into two categories: one is the substitution effect of Mg2+ ions and the other is the “composite” effect of MgO.