Call for Detroit Meeting Electronics Division Recent News PapersTriplicate copies of a 75-word Abstract of Recent News Papers must be received by the Symposium Chairman (as indicated below) not later than September 1, 1969. Electronics Division General SemiconductorGeneral Sessions Recent News Papers are to be sent to M. E. Jones, Texas Instruments, 13500 No. Central Expressway, Dallas, Texas 75222. Area of interest relate to elemental alloy and compound semiconductors and include: (1) Ma-teriais synthesis and characterization, and (2) Device Technology.

No abstract

The rest potential of a platinum bead electrode in oxygen-stirred acid solution was investigated as a function of the pH, the partial pressure of oxygen, and the history of electrode preparation. It is believed that the theoretical equilibrium oxygen potential, +1.229v vs. N.H.E., cannot be obtained in any ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 131.215.225.9 Downloaded on 2015-05-28 to IP Vol. 109, No. 9 REST POTENTIALS bottom of each inlet tube is placed a ball of platinum gauze to break the gas stream into fine bubbles. Finally, a small hole, through which a thin platinum wire may be inserted as a pre-electrolysis electrode, is made in each top. ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 131.215.225.9 Downloaded on 2015-05-28 to IP ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 131.215.225.9 Downloaded on 2015-05-28 to IP Vol. 109, No. 9 REST POTENTIALS IN Pt-O-ACID SYSTEM 865When these substances are present the system becomes more reversible.

Steady‐state polarization curves and cyclic voltammograms were obtained on Pt microelectrodes in various solutions in Ni ions. The data indicated that at a Pt surface in a solution of NiSO4 , H2 was deposited before the metallic Ni layer was laid down. In the Watts bath (containing NiSO4 , NiCl2 , and boric acid), the Ni layer was deposited before H2 was evolved. The presence of boric acid lowers the overvoltage for Ni deposition.

Cyclic voltammograms were obtained on gold bead microelectrodes in N2‐normalstirred 1M H2SO4 and 1MHF solutions as a function of the sweep rate and the potential range scanned. It is found that H2 and O2 are very slightly absorbed on Au and that neither is dissolved in the bulk metal. As a result, Au makes a more stable indicator electrode than Pt, which does dissolve oxygen. It is the formation of this Pt‐O alloy that necessitates a prepolarization of Pt before a steady‐state cyclic voltammogram is obtained. It is noted that all contamination of Au with noble metals must be rigorously avoided.

Steady‐state polarization measurements were made on Pt bead cathodes in N2‐normalstirred solutions of Na2CrO4 , Na2Cr2O7 , and chromic acid. Three main regions can be distinguished: oxide reduction, H2 evolution, and Cr(VI) reduction to Cr(III) or to black Cr or both. To obtain the black Cr deposit, a polychromate must be present and a low pH must be maintained. Steady‐state polarization measurements were made on Pt bead cathodes in N2‐normalstirred solutions of Na2CrO4 and Na2Cr2O7 to which Na2SO4 had been added and of chromic acid to which Na2SO4 or H2SO4 had been added. These data indicate that the active catalyst is HSO4− ion which catalyzes only the reduction of the chromous products of the reduced cathode film. Bisulfate ion also acts as a blocking agent which inhibits electron transfer to chromium ions. A detailed mechanism for the reduction of Cr(VI) solutions to Cr metal is proposed. To prevent the formation of stable normalCrfalse(H2O)6+3 complexes, a cathodic film of chromic dichromate is formed with one end blocked by complexing with HSO4− ions. Decomposition of the film by reaction with H3O+ ions produces chromous hydroxide, the reduction of which to metallic Cr is catalyzed by HSO4− ions. By the concept of a distribution function of trichromatebisulfate complexes, the narrow range of HSO4− ion concentrations which must be controlled to maintain successful Cr deposition is made understandable.

No abstract

The potential of saturated α-palladium in hydrogen-stirred solution compared to a Pt/H2 electrode in the same solution is 0.0495±0.0005 v. The potential-determining reaction on α-palladium is independent of hydrogen pressure. The potential-determining equilibrium is postulated to be, H++e= lim Pd(Pd−H)α. Pure palladium spontaneously absorbs hydrogen in hydrogen-stirred solution until the saturation limit of the α phase is reached. This limiting atomic ratio of H/Pd=0.025±0.005. Between a H/Pd atomic ratio of 0.03 to 0.36 both the α and β phases coexist and the mixed potential is determined by that of the α domains. In the H/Pd region 0.36 to 0.6, the potential is a function of the hydrogen content of the palladium.