Dielectric elastomer actuators (DEA) consist of a thin dielectric elastomer film sandwiched between two compliant electrodes. The force and deformation provided by these actuators depend substantially on the electrical and mechanical material properties of the dielectric film. By incorporating barium titanate (BaTiO3) particles into an elastomer matrix, the fabrication of polymer composites with increased permittivity is enabled. Within this work, the influence of different BaTiO3 particle concentrations in a soft silicone matrix is investigated by impedance spectroscopy and tensile tests. The identified correlations allow for the application-dependent adjustment of the material properties by varying the BaTiO3 concentration. To show the feasibility of this method, dielectric films of the composite are used to manufacture DEAs and their performance is evaluated.