Dielectric properties of barium titanate and alumina filled epoxy

The properties of a dielectric material can be controlled through the introduction of various fillers. This study was primarily undertaken to determine the effect of the combination of two fillers, barium titanate, to increase the permittivity of the filled system, and alumina, for its antitracking properties. It was found that the introduction of barium titanate filler into epoxy produced samples which exhibited increased permittivity with increasing filler level. The addition of only alumina filler also increased the permittivity of the base epoxy, although to a lesser extent. To evaluate the interaction of these two fillers, samples were prepared holding one filler level constant and varying the level of the other material. It was found that samples prepared with a mixture of both the alumina and barium titanate fillers exhibited a permittivity that was slightly higher than that of samples filled with barium titanate alone