Effects of current density and electrolyte temperature on the volume expansion factor of anodic alumina formed in oxalic acid

TY - JOUR

T1 - Effects of current density and electrolyte temperature on the volume expansion factor of anodic alumina formed in oxalic acid

AU - Zhou, F.

AU - Baron-Wiecheć, A.

AU - Garcia-Vergara, S. J.

AU - Curioni, M.

AU - Habazaki, H.

AU - Skeldon, P.

AU - Thompson, G. E.

N1 - Funding Information: The authors thank Drs I. Vickridge and E. Briand of the Institut des Nano Sciences de Paris for assistance with RBS/NRA, and the Engineering and Physical Sciences Research Council (U.K.) for financial support (Programme Grant: LATEST2 ). They also wish to acknowledge the support of the European Community ’s Seventh Framework Programme FP7/2007-2013, under grant agreement no. PIEF-GA-2008-219913 .

PY - 2012/1/1

Y1 - 2012/1/1

N2 - The formation of porous anodic alumina in 0.4 M oxalic acid is investigated over a range of current density and electrolyte temperature using sputtering-deposited substrates containing tungsten tracer layers. The findings reveal volume expansion factors and efficiencies of film growth that increase with the increase of the current density and decrease of the temperature. Pore generation by the flow of the anodic alumina in the barrier layer toward the pore walls is proposed to dominate at relatively high current densities (above ∼2 mA cm -2), with tungsten tracer species being retained within films. Conversely, losses of tungsten species occur at lower current densities, possibly due to increased field-assisted ejection of Al 3+ ions and/or field-assisted dissolution of the anodic alumina.

AB - The formation of porous anodic alumina in 0.4 M oxalic acid is investigated over a range of current density and electrolyte temperature using sputtering-deposited substrates containing tungsten tracer layers. The findings reveal volume expansion factors and efficiencies of film growth that increase with the increase of the current density and decrease of the temperature. Pore generation by the flow of the anodic alumina in the barrier layer toward the pore walls is proposed to dominate at relatively high current densities (above ∼2 mA cm -2), with tungsten tracer species being retained within films. Conversely, losses of tungsten species occur at lower current densities, possibly due to increased field-assisted ejection of Al 3+ ions and/or field-assisted dissolution of the anodic alumina.

KW - Aluminium

KW - Anodizing

KW - NRA

KW - Oxalic acid

KW - RBS

UR - http://www.scopus.com/inward/record.url?scp=84655163895&partnerID=8YFLogxK

U2 - 10.1016/j.electacta.2011.10.052

DO - 10.1016/j.electacta.2011.10.052

M3 - 文章

AN - SCOPUS:84655163895

SN - 0013-4686

VL - 59

SP - 186

EP - 195

JO - Electrochimica Acta

JF - Electrochimica Acta

ER -