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Article
A Model for Coupled Electrical Migration and Stress-Driven Transport in Anodic Oxide Films
Journal of the Electrochemical Society
  • Kurt R. Hebert, Iowa State University
  • Jerrod E. Houser, Iowa State University
Document Type
Article
Disciplines
Publication Date
1-1-2009
DOI
10.1149/1.3151835
Abstract

A model for transport in amorphous anodic oxide films was developed in which ion migration was driven by gradients of mechanical stress as well as electric potential and which included viscoelastic creep of the oxide. Simulations were presented for the galvanostatic growth of planar barrier-type anodic aluminum oxide films. It is assumed that stress originates at the metal-film interface due to the volume change upon oxidation. The average stress in the film decayed during growth and evolved from compressive to tensile with increasing applied current density. The model was fit to stress-thickness measurements using a viscosity of 1×1012Pas on the same order of magnitude as that of many other amorphous materials displaying viscous creep. The current density increased exponentially with electric field, in agreement with an empirical high field conduction behavior. The metal ion transport number was predicted based on the motion of markers in the film and increased with current density in quantitative agreement with experimental measurements. The model represents a unified quantitative interpretation of ionic conduction, transport numbers, and mechanical stress measurements in anodic films.

Comments

This article is from Journal of the Electrochemical Society 156 (2009): C275–C281, doi:10.1149/1.3151835. Posted with permission.

Copyright Owner
ECS—The Electrochemical Society
Language
en
File Format
application/pdf
Citation Information
Kurt R. Hebert and Jerrod E. Houser. "A Model for Coupled Electrical Migration and Stress-Driven Transport in Anodic Oxide Films" Journal of the Electrochemical Society Vol. 156 Iss. 8 (2009) p. C275 - C281
Available at: http://works.bepress.com/kurtr_hebert/12/