Transient thermal stress analysis of CeO₂ thin films on Ni substrates using finite element methods for YBCO coated conductor

The effect of residual stresses of CeO₂ buffer layers on Ni substrate for YBCO coated conductors is considered. CeO₂ films were fabricated on Ni tape substrate from the solutions prepared from alkoxide precursors, solvent, chelating agent and modifying liquid material by using a reel-to-reel sol-gel technique. SEM observation showed that CeO₂ buffer layers had crack-free, pinhole-free and continuous structures and the characteristic feature of the films was grain boundary grooves. Finite element method (FEM) was used to compute the temperature and stress fields of the sample with CeO₂/Ni configuration. The solution was obtained by ANSYS 5.4 analysis programme. The effect of time and residual stresses of the films with different thickness was examined in terms of the FEM results. It was found that the positions of the improved temperature and thermal stresses were considerably affected material properties, time and film thickness for CeO₂ buffer layers and the thermal stresses values increased upon increasing the film thickness.