Enhancement of Dielectric Constants in Strontium Titanate through Mg and Al Doping

Abstract

Dielectric capacitors can be utilized in powder conversion systems of applications such as hybrid-electric and fuel cell vehicles. In order to fabricate capacitors that are suitable for practical uses, the materials should have moderately high dielectric constants, while retaining low loss. In this study, strontium titanate and strontium titanate samples doped with 10, 20, 30 at% of Mg and Al were tested for dielectric permittivity and dielectric loss. The results indicated that an increase in the amount of dopants led to enhancement of dielectric constants. The value of dielectric constant of strontium titanate with 30 at% Mg was four times higher than that of the undoped strontium titanate, while the samples with 30 at% Al could achieve the dielectric constant five times higher than that of the undoped sample. Low dielectric loss, in the range between 0.001-0.024, was observed.