Dielectrical Properties of CeO2 Nanoparticles at Different Temperatures

• Autor(a) principal: Zamiri, Reza
• Data de Publicação: 2015
• Outros Autores: Ahangar, Hossein Abbastabar, Kaushal, Ajay, Zakaria, Azmi, Zamiri, Golnoosh, Tobaldi, David, Ferreira, J. M. F.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/20490
• topic: CERIUM OXIDE NANOPARTICLES; PRECIPITATION METHOD; PARTICLES; POWDERS; NANOSTRUCTURES; HYDROLYSIS; TRANSPORT; NANORODS

A template-free precipitation method was used as a simple and low cost method for preparation of CeO2 nanoparticles. The structure and morphology of the prepared nanoparticle samples were studied in detail using X-ray diffraction, Raman spectroscopy and Scanning Electron Microscopy (SEM) measurements. The whole powder pattern modelling (WPPM) method was applied on XRD data to accurately measure the crystalline domain size and their size distribution. The average crystalline domain diameter was found to be 5.2 nm, with a very narrow size distribution. UV-visible absorbance spectrum was used to calculate the optical energy band gap of the prepared CeO2 nanoparticles. The FT-IR spectrum of prepared CeO2 nanoparticles showed absorption bands at 400 cm(-1) to 450 cm(-1) regime, which correspond to CeO2 stretching vibration. The dielectric constant (er) and dielectric loss (tan delta) values of sintered CeO2 compact consolidated from prepared nanoparticles were measured at different temperatures in the range from 298 K (room temperature) to 623 K, and at different frequencies from 1 kHz to 1 MHz.