Influence of Nd_2O_3 Doping on the Dielectric Properties of BSTO/MgO

Based on w(MgO)% =58% magnesia mixed with Ba0.55Sr0.45TiO3(BSTO),undoped and Nd2O3 doped(0.3,0.5,0.7,1.5mol%)Ba0.55Sr0.45TiO3/MgO composite were prepared by traditional ceramic process-solid phase synthesis and their microstructure and dielectric properties were systemically studied.XRD and SEM analyses showed that the BSTO/MgO composite containd a pure perovskite phase and the grain size of BSTO/MgO composite became smaller with the increasing of the amount of Nd2O3.It was found that proper amount of Nd2O3 could reduce the loss tangents of BSTO/MgO composite at high frequency and ensured moderate dielectric constant.However,excessive amount of Nd2O3 would lower dielectric constant.The BSTO/MgO composit with 0.3mol% Nd2O3 possesses excellent dielectric properties:er = 88,tanδ = 2.8×10-3(at 4.1 GHz)and tunability=6.9%(at external DC field E=2.0 kV/mm).