| In order to obtain a kind of dielectric material with high energy storage density, xBi(Mg2/3Nb1/3)O3-(1-x)BaTiO3(xBMN-(1-x)BT) system was studied in this paper. The dielectric materials with good stability, high breakdown strength and high energy storage density are expected. Therefore glass and oxide were added to modify xBMN-(1-x)BT ceramic to improve the energy storage. The research work was carried out as following:(1)xBMN-(1-x)BT(x=0.1,0.2,0.3,0.4,0.5) ceramics were synthesized by traditional solid state method. The phase structure,microstructure,dielectric properties of xBMN-(1-x)BT were studied. The sintering temperature was reduced and obvious relaxation occurred with the increase of BMN content. The ceramics have relative best properties when x=0.1, which was sintered at1260℃with breakdown strength of182kV/cm and energy storage density of1.16J/cm3. So, the0.1BMN-0.9BT was selected as a based material to be modified in the following study.(2)ZnO-B2O3-SiO2oxide mixture was prepared by traditional solid state method and was added to0.1BMN-0.9BT ceramics with different ratio (2wt%,4wt%,6wt%,8wt%and10wt%). The results indicated that the leakage current increased and the resistance and breakdown strength decreased because of the high ZnO content of the additive.(3)ZnO-B2O3-SiO2(ZBS) glass(40mol%ZnO-35mol%B2O3-25mol%SiO2) was synthesized by traditional solid state method and was added to0.1BMN-0.9BT ceramics with different ratio(2wt%,4wt%,6wt%,8wt%and10wt%).It showed that the sintering temperature and microstructure were improved by adding ZBS glass. The dense ceramics with good microstructure was achieved when the addition content of ZBS glass was6wt%. The breakdown strength and energy storage density were improved.0.1BMN-0.9BT ceramic with6wt%ZBS glass obtained maximum breakdown strength(228kV/cm) and maximum energy storage density(1.40J/cm3). It showed that adding glass can improve the energy storage properties of ceramics to a certain extent. |
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