Structures and properties of Ba0.3Sr0.7TiO3: MgTiO3 ceramic composites

Ceramic composites of barium strontium titanate (Ba0.3Sr0.7TiO3) mixed with magnesium titanate (MgTiO3, in a range of 5 to 40 mol%) were prepared and studied. At the low MgTiO3 content (5%), a solid solution of Ba0.3Sr0.7TiO3 with MgTiO3 is observed at 1250 °C and the solubility is extended to 40% MgTiO3 when the sintering temperature increases to 1350 °C. When sintered at 1250 °C, the dielectric constant and microwave property Qxf values of composites decrease with increasing MgTiO3 content due to the dilution effect of MgTiO3 phase. Sintering at 1350 °C results in an enhanced microwave property, attributed to the single phase of Ba0.3Sr0.7TiO3 and large grained structures. With 10% MgTiO3 sintered at 1350 °C, the dielectric constant is 365 and the Qxf value is 1467 GHz indicating their potential in microwave applications.