caa a22 4500 477050506 CHVBK 20180405111339.0 cr unu---uuuuu 170330e19961001xx s 000 0 eng 10.1007/BF00242198 doi (NATIONALLICENCE)springer-10.1007/BF00242198 Anion incorporation and its effect on the dielectric constant and growth rate of zirconium oxides [Elektronische Daten] [M. Abdel Rahim, A. Abdel Rahman, M. Khalil] Mechanically polished zirconium electrodes were potentiodynamically polarized in phosphate buffer solutions of various pH values and in 0.5 lvl NaOH. The results show that the shape of the I-E curves is independent of the solution pH. At relatively low scan rates, oxygen gas evolution was observed. The oxide film thickness was calculated from the values of the charge consumed in the anodic process assuming 100% current efficiency for oxide formation below oxygen evolution (lower values for the current efficiency are assumed for potentials above oxygen evolution). Capacitance measurements, together with the calculated oxide thickness, were used to estimate values for the dielectric constant of the oxide. Two different values of the dielectric constant were obtained for the oxides formed in the range of potential below and above oxygen evolution. Also, higher dielectric constant values were obtained with increasing solution pH. Anion incorporation was assumed to increase the conductivity of the oxide films and, hence, decrease the dielectric constant. A two-layer structure is proposed for the anodically formed oxide on zirconium in aqueous solutions; an anion-free layer near the metal and an outer layer containing the incorporated anions. Chapman & Hall, 1996 Abdel Rahim M. Department of Chemistry, Faculty of Science, Cairo University, Giza, Egypt aut Abdel Rahman A. Department of Chemistry, Faculty of Science, Cairo University, Giza, Egypt aut Khalil M. Department of Chemistry, Faculty of Science, Cairo University, Giza, Egypt aut Journal of Applied Electrochemistry Kluwer Academic Publishers 26/10(1996-10-01), 1037-1043 0021-891X 26:10<1037 1996 26 10800 https://doi.org/10.1007/BF00242198 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00242198 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Abdel Rahim M. Department of Chemistry, Faculty of Science, Cairo University, Giza, Egypt aut NATIONALLICENCE 700 1- Abdel Rahman A. Department of Chemistry, Faculty of Science, Cairo University, Giza, Egypt aut NATIONALLICENCE 700 1- Khalil M. Department of Chemistry, Faculty of Science, Cairo University, Giza, Egypt aut NATIONALLICENCE 773 0- Journal of Applied Electrochemistry Kluwer Academic Publishers 26/10(1996-10-01), 1037-1043 0021-891X 26:10<1037 1996 26 10800 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer