Benrath and Ruland1) were the earliest to investigate the oxidizing action of ceric sulfate on several substances, while Lejune3) studied the oxidizability of alcohols, aldehydes and ketones by potassium permanganate and potassium dichromate.Later Willard and Young3) observed the unreactivity of formic and acetic acids towards ceric sulfate and complicated kinetics and stoichiometry in the case of tartaric, malonic and other acids. Ross and Swain4) tried to apply the principle of the concentration cells to kinetic studies on the oxidation of oxalic acid by ceric sulfate. The work of Shorter and Hinshelwood5) concerned the oxidation of acetone6) by ceric sulfate in dilute sulfuric acid. They assumed direct reaction between trisulfato-hydroxy cerate ion {H2CeOH(SO4)3}-with enolic form of acetone. Hargreaves and Sutcliffe7), using rather high concentrations of sulfuric acid, found the rate of oxidation of formaldehyde to depend on the cubic exponent of sulfuric acid concentration, indicating tetra-sulfate ceric acid H4Ce-(SO4)4 to be the reactive species. Dodson and Black8) favored the existence of the trisulfato cerate ions Ce(SO4)32-in soulution and assumed the main reductant to be the bioxalate ion HC2O4-. Shao Minchzhou and Gorbachev') 1) A.

The oxidation of methyl alcohol by ceric perchlorate in perchloric acid solution was studied at 13, 20 and 26°C. The stoichiometry consisted of two cerie ions for the oxidation of one molecule of methanol. While the rate of disappearance of ceric ions directly depended on the concentration of ceric ions, the dependence on methanol concentration was such as to suggest a ‘broken order’: \frac−dCeivdt=\frack(Ceiv)(MeOH)1+k′(MeOH) This rate also depended on the concentration of perchloric acid in such a way that at high acidity it became independent of it. These data were explained on the basis of Duke’s mechanism for 2,3-butane diol-ceric perchlorate reaction, i. e. the oxidation of methanol by ceric ions proceeded via an intermediate complex between one Ce4+ ion and one methanol molecule. The formation of this complex was also proved independently by a spectrophotometric method. The kinetic data were further used to derive the true heat of formation of the methanol-cerate complex and the heat of hydrolysis of the cerie ions in aqueous perchloric acid.

No abstract

Thin films of various thicknesses in the MIM structure have been prepared from the powder of SnO,/Sb,O, mixed sample by the thermal evaporation technique in a vacuum of Torr. Dielectric properties of Sn02/Sb,03 mixed thin films have been studied with temperature starting from LNT to RT and above RT and frequency ranging from 100Hz to 16kHz. The activation energy for the migration of charge carriers in SnO,/Sb,O, mixed thin films has been calculated and it is found to be 0.23 eV. The results thus obtained on dielectric properties of SnO,/Sb,O, mixed thin films are presented and discussed. WILLIAMS G. HYNES, RICHARD H. BUBE: J. Appl. Physics 49 (1978) 304 Let. 2 (1983) 63 and their mixed thin