New advances in printed circuit boards have yielded promising applications, especially concerning sensors and wireless identification devices. However, such devices require improved high-κ dielectric capacitors that avoid high temperature treatments. Barium titanate (BaTiO₃) is a ferroelectric material commonly used as a dielectric material in existing capacitors. Without excessive heating, the dielectric properties of barium titanate can be improved with the addition of conductive nanoparticles to the BaTiO₃ surface. Gold nanoparticles are ideal for their ability to disperse in water without agglomerating over time.

Starting with commercially available 100 nm barium titanate nanoparticles and smaller (15-20 nm) gold nanoparticles, a composite was produced via heterocoagulation. Modification of the BaTiO₃ and gold surfaces creates electrostatically attractive forces that maintain order and avoids the self-agglomeration of gold particles into connective pathways. Characterization of the particles included single-point and pH-dependent Zeta-potential measurements. SEM images of the dry material revealed the presence of well-dispersed gold nanoparticles on the surface of the 100 nm barium titanate particles. The dielectric constant was measured on freeze-dried and pressed pellets. Optimization of the dielectric constant by varying the gold concentration was also explored.