CuO/Ta2O5 core/shell nanoparticles synthesized in immersed arc-discharge: production conditions and dielectric response

We reported recently on a novel nanostructured material produced by the arc-discharge in water method, and extended studies were realized to identify the nature of this material, i.e., CuO/Ta2O5 core/shell crystalline nanoparticles (NPs). As a continuation of this investigation on the possibility of complex NP synthesis using immersed arc-discharge, the production conditions of the CuO/Ta2O5 NPs are herein presented in detail and the electrical properties of the nanopowder are examined comprehensively. The discharge is thus probed in situ by electrical measurements, optical emission spectroscopy and high speed imaging, and the electrical behavior of the NPs is considered by means of broadband dielectric spectroscopy. This combined study provides an integrated characterization of this new material, unveils its potential applications, and makes available suggestions on the process control.