Journal ArticleDOI
Electrical Conductivity and Lattice Defects in Nanocrystalline Cerium Oxide Thin Films
TLDR
In this article, the results of the electrical conductivity and Raman scattering measurements of CeO2 thin films obtained by a polymeric precursor spin-coating technique are presented.Abstract:
The results of the electrical conductivity and Raman scattering measurements of CeO2 thin films obtained by a polymeric precursor spin-coating technique are presented. The electrical conductivity has been studied as a function of temperature and oxygen activity and correlated with the grain size. When compared with microcrystalline samples, nanocrystalline materials show enhanced electronic conductivity. The transition from extrinsic to intrinsic type of conductivity has been observed as the grain size decreases to <100 nm, which appears to be related to a decrease in the enthalpy of oxygen vacancy formation in CeO2. Raman spectroscopy has been used to analyze the crystalline quality as a function of grain size. A direct comparison has been made between the defect concentration calculated from coherence length and nonstoichiometry determined from electrical measurements.read more
Citations
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Superoxide dismutase mimetic properties exhibited by vacancy engineered ceria nanoparticles
TL;DR: In this report ceria nanoparticles are shown to act as catalysts that mimic superoxide dismutase (SOD) with the catalytic rate constant exceeding that determined for the enzyme SOD.
Journal ArticleDOI
One-dimensional titanium dioxide nanomaterials: nanotubes.
TL;DR: The present review tries to give a comprehensive and most up to date view to the field, with an emphasis on the currently most investigated anodic TiO2 nanotube arrays.
Journal ArticleDOI
Nanostructured ceria-based materials: synthesis, properties, and applications
Chunwen Sun,Hong Li,Liquan Chen +2 more
TL;DR: In this article, the authors present the recent technological and theoretical advances related to the CeO2-based nanomaterials, with a focus on the synthesis from one dimensional to mesoporous ceria as well as the properties from defect chemistry to nano-size effects.
Journal ArticleDOI
Rare earth nanoparticles prevent retinal degeneration induced by intracellular peroxides
TL;DR: The data indicate that the nanoceria particles may be effective in inhibiting the progression of ROI-induced cell death, which is thought to be involved in macular degeneration, retinitis pigmentosa and other blinding diseases, as well as the ROi-induced death of other cell types in diabetes, Alzheimer's disease, atherosclerosis, stroke and so on.
Journal ArticleDOI
Cerium oxide nanoparticle: a remarkably versatile rare earth nanomaterial for biological applications
Can Xu,Xiaogang Qu +1 more
TL;DR: The need for systematic biological testing is stressed, however, to resolve possible toxicity concerns of Cerium oxide nanoparticles, which mimic enzyme species that repair the damage caused by free radicals and reduce harmful reactive oxygen levels in the body.
References
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Journal ArticleDOI
The one phonon Raman spectrum in microcrystalline silicon
H. Richter,Z. P. Wang,Lothar Ley +2 more
TL;DR: In this paper, a relaxation in the q-vector selection rule for the excitation of the Raman active optical phonons was proposed to increase the red shift and broadening of the signal from microcrystalline silicon films.
Journal ArticleDOI
Raman study of CeO2: Second-order scattering, lattice dynamics, and particle-size effects.
TL;DR: It is shown using the calculated dispersion curves that this particle-size effect cannot be explained with the spatial-correlation model.
Journal ArticleDOI
Small polaron electron transport in reduced CeO2 single crystals
Harry L. Tuller,A.S. Nowick +1 more
TL;DR: In this paper, the authors investigated the electrical properties of reduced ceria, CeO 2− x, carried out on single crystals, and showed that the Seebeck coefficient is independent of temperature, suggesting that the number of carriers is constant.
Journal ArticleDOI
Raman Scattering in Alloy Semiconductors: "Spatial Correlation" Model
P. Parayanthal,Fred H. Pollak +1 more
TL;DR: Using a spatial correlation model with a Gaussian correlation function, the authors quantitatively explained the broadening and asymmetry of the first-order longitudinal-optic phonon Raman spectrum induced by alloy potential fluctuations.
Journal ArticleDOI
A thermodynamic study of nonstoichiometric cerium dioxide
TL;DR: In this paper, the deviation from stoichiometry x = x(T, Po2) was determined from measurements performed on nonstoichiometric CeO2−x in the temperature range 750-1500°C and from oxygen pressures of 10−2 to 10−26 atm.