Dielectrical Properties of CeO2 Nanoparticles at Different Temperatures

Abstract

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 (εr) and dielectric loss (tan δ) 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.

Amorphizing of Au Nanoparticles by CeOx–RGO Hybrid Support towards Highly Efficient Electrocatalyst for N2 Reduction under Ambient Conditions

“…The Raman spectra of both the a ‐Au/CeO x –RGO and c ‐Au/RGO hybrids show the existences of the D (1348 cm −1 , arising from the disordered carbon atoms) and G bands (1595 cm −1 , corresponding to the graphitic hexagon‐pinch mode) . Moreover, one Raman peak, which is attributed to the triply degenerate F 2g mode of the fluorite crystal structure of CeO 2 , centered at about 453 cm −1 is shown in the a ‐Au/CeO x –RGO hybrid, which is considered as the symmetric stretching mode of O atoms around Ce ions . Comparing with the Raman peak of bulk CeO 2 at 465 cm −1 , the Ce 3+ ions in the samples can be responsible for the blueshift of the main peak in the Raman scattering, which is also measured in X‐ray photoelectron spectroscopy (XPS) results.…”

Hydrothermal Synthesis of Gadolinium (Gd) Doped Cerium Oxide (CeO2) Nanoparticles: Characterization and Antibacterial Activity

“…The cerium oxide nanoparticles (CeO 2 NP s ) have unique structure because of their broad applicability to various areas such as microelectronics, optoelectronics, fuel cell technologies, gas sensors, solid state electrolytes and antimicrobial activities [2][3][4] . There are several methods have been proposed for the synthesis of CeO 2 nanoparticles [5][6][7][8] . The hydrothermal method has advantages over other methods such as efficient synthesis process and morphology controlled growth.…”

Synthesis, characterization and dielectric properties of $$\hbox {TiO}_{2}$$ TiO 2 – $$\hbox {CeO}_{2}$$ CeO

“…The experimental values of dielectric constant and dielectric loss for all ceramic nanocomposites (TiO 2(x) -CeO 2(1−x) (x = 0.05, 0.10, 0.15 and 0.20)) were found to be stable up to 250 • C and thereafter, an increment with temperature was observed. The increase of dielectric constant beyond 250 • C may be due to the increased polarization with the applied field, which cause an interaction between the field and the dielectric polarization with temperature [62]. The dielectric characteristics were found to be 27. which may be associated with high dielectric constant of TiO 2 nanoparticles.…”