ABSTRACT
Electrochemical Vapor Deposition (EVD) has become a key technology for depositing gas impervious films of YSZ on porous substrates. The kinetics of film growth of YSZ can be modeled in detail considering the Wagner oxidation process. According to this model the electron diffusion is predicted to be rate limiting. However, the apparent activation energy of the observed growth is not equal to the activation enthalpy for electron conduction in YSZ. This inconsistency can be understood considering the thermodynamic equilibrium at the gas-solid interphases. The calculated thermodynamic equilibrium is used to predict the growth rate. The results show that the EVD growth of YSZ is most likely governed by defect transport in the EVD layer, and a mass transfer limitation at the surface at the metal chloride side.
