Microwave Dielectric Properties of Ba₂Ti₉O₂₀ Ceramics Coated by Precursor Solution of CuSO₄

Ba2Ti9O20 main phase are prepared from BaCO₃ and TiO₂ powders.The CuO doped by precursor solution of CuSO₄ was used to reduce the sintering temperature of the Ba2Ti9O20 ceramics.modifying the surface of Ba₂Ti₉O₂₀ by CuO thin layer.The process reduces the amount of sintering aid and minimized the negative impact of sintering aid on dielectric properties.The relative dielectric constant（εr） increased initially and then decreased slightly with increasing CuS_O4 concentration.The dielectric loss（tanδ） decreased initially and then increased with the addition of CuSO₄ solution.Good dielectric properties of εr = 43,tanδ = 0.005 and τf =-7 ppm/℃（1MHz） were obtained for the 0.32 mol/l CuSO₄ concentration added Ba2Ti9O20 ceramics sintered at 1200 ℃ for 4 h.