Structure and dielectric property of Bi3NbZrO9 doped BST ceramics sintered at low temperature

Abstract

ABSTRACTBa0.65Sr0.35TiO3-x Bi3NbZrO9 (BST-x Bi3NbZrO9, x = 0.5, 1, 3, 5, 7 wt.%) ceramics sintered at low temperature were prepared by traditional solid state reaction method. Influence of Bi3NbZrO9 doping amount on the dielectric properties and microstructure of (Ba, Sr)TiO3(barium strontium titanate, BST) capacitor ceramics by means of X-ray diffraction(XRD), Scanning electron microscopy (SEM) and traditional solid state sintering method. The results showed that the impurity materials phase were appeared when Bi3NbZrO9 doping amount increased. When Bi3NbZrO9 doping amount increased, dielectric constant(ϵr)increased firstly and then decreased and then increased, dielectric loss(tanδ) decreased firstly and then increased, the capacitance temperature changing rate(ΔC/C) decreased. When Bi3NbZrO9 doped amount was 1 wt.% and the sintered temperature was 1280°C, the BST ceramics possessed good comprehensive property with ϵr of 2325, tanδ of 0.0048, Eb of 7.8 kV/mm(AC), ΔC/C of −12.9∼14.3% in the temperature range of −30°C∼85°C and the capacitance temperature characteristic was consistent with Y5R.