Electrical characteristics of Al2O3 and Ta2O5 nanoparticles synthesized by DC anodic ARC-discharge in water

Because of the length scale and high specific surface area of nanometer-sized particles, they exhibit novel properties as compared with their bulk counterpart materials. Furthermore, the incorporation of well-characterized nanoparticles in various organic matrices provides dielectrics with improved electrical, mechanical and thermal features. Alumina and tantalum-pentoxide nanoparticles have been proved efficient fillers in such nanocomposites. These specific particles are herein produced by DC anodic arc-discharge immersed in water and they are probed by means of broadband dielectric spectroscopy in a wide temperature range (-100 to 100 °C). Different formalisms (effective dielectric constant, loss factor and specific conductivity) are combined, providing the possibility to determine the frequency and temperature dependence of the dielectric characteristics of the synthesized nanoparticles. The knowledge of the latter should be determinant for potential application of alumina and tantalum-pentoxide fillers to two-phase heterogeneous nanodielectrics.