Energy storage density and tunable dielectric properties of BaTio.85Sno.15O3/MgO composite ceramics prepared by SPS

(100-X) wt.% BaTiossSn(0.15)O(3)-X wt.% MgO(BTS/MgO) composite ceramics were prepared by spark plasma sintering (SPS) technology. Phase constitution, microstructure, dielectric and electrical energy storage properties of BTS/MgO composite ceramics were investigated. The samples prepared by SPS had smaller grain size and presented layer-plate substructure. Dielectric permittivity and dielectric loss of BTS/MgO composite ceramics decreased significantly with the content of MgO increasing, and dielectric tunability maintained a relatively high value (>45%). Meanwhile, the dielectric breakdown strength was improved when addition of MgO in BTS matrix, which resulted in a significant improvement of energy storage density. The high dielectric breakdown strength of 190 kV/cm, energy storage density of 0.5107 J/cm(3) and energy storage efficiency of 92.11% were obtained in 90 wt.% BaTi0.(85)Sno.O-15(3)-10 wt.% MgO composite ceramics. Therefore, BTS/MgOcomposites with good tunable dielectric properties and electrical energy storage properties could be exploited for energy storage and phase shifter device applications. (C) 2016 Elsevier Ltd. All rights reserved.