The silicon–cerium oxide interface is studied using x-ray photoelectron spectroscopy. The oxidation and reduction of species at the interface are examined as a function of annealing temperature both in vacuum and oxygen ambient, in order to determine their relative stabilities. By depositing a very thin CeO2 film ~;30 Å!, the cerium and silicon core level peaks can be monitored simultaneously. ...

The rare earth cerium was found to bind rapidly to Escherichia coli. Cerium inhibited oxygen uptake in the presence of glucose as well as the endogenous respiration of glucose-grown cells. For a cell concentration of 4 mg per ml, maximal inhibition was obtained at 120 mug per ml. Greater concentrations did not increase the inhibitory effect. Cerium inhibited (14)CO(2) evolution and (14)C uptake...

Cerium oxides have attracted much attention because of their uses in three-way catalysts and other catalyst applications. The redox reaction of cerium oxides, as the basis of their use as catalysts, usually takes place at high temperature (>600 K) and/or low oxygen partial pressure. There have been continuous efforts to lower the operating temperatures of cerium oxide further to improve the per...

In the present study, a conversion layer mainly composed by cerium oxide was prepared by means of a novel ultrasound-assisted coating process. The formation of a conversion layer on top of the Mg alloy provides physical barrier properties improving the corrosion protection. In addition, the incorporation of cerium oxide within the coating enables the formation of a protective layer on the pores...

These compounds crystallize in the hexagonal structure (space group P63/m) related to the Gd6Co1.67Si3-type. The magnetization measurements reveal that: (i) the cerium exhibits a trivalent state in Ce6Co1.67Si3 but no magnetic ordering is evidenced above 1.8 K; (ii) on the contrary, two ferro(ferri)magnetic transitions are detected for Nd6Co1.67Si3 (84 K and 35 K) and Tb6Co1.67Si3 (183 K and 39...

A simple and sensitive kinetic spectrofluorometric method was developed for the determination of some calcium channel blockers namely, verapamil hydrochloride, diltiazem hydrochloride, nicardipine hydrochloride and flunarizine. The method is based upon oxidation of the studied drugs with cerium (IV) ammonium sulphate in acidic medium. The fluorescence of the produced Ce (III) was measured at 36...

The X-ray structural characterization of tritylphosphonic acid, Ph3CPO3H2 (), reveals that it possesses three different structural forms (a hexameric cage, a two-dimensional polymeric sheet and a dimer) depending upon the solvent used for crystallization. The reaction of cerium nitrate with under solvothermal conditions afforded a molecular dinuclear Ce(III) phosphonate, [Ce2{Ph3CPO2(OEt)}4(NO3...

In this paper, various microstructures of Ce2(WO4)3 and Ce10W22O81 were prepared by applying a hydrothermal synthesis, in a ligand-free environment, and in the presence of a dioctyl sodium sulfosuccinate (DSS) surfactant, after which the materials were heat treated at a temperature of 900 °C. Depending on the ratio of cerium ions to sodium tungstate, as well as the reaction pH, two different ce...

We have successfully determined the hitherto unknown sign of the B(4)(4) Stevens crystal-field parameter of the tetragonal heavy-fermion compound CeCu(2)Si(2) using vector q-dependent nonresonant inelastic x-ray scattering experiments at the cerium N(4,5) edge. The observed difference between the two different directions, q∥[100] and q∥[110], is due to the anisotropy of the crystal-field ground...