Direct Observation of Unequal Lattice Change of Ceramics Thin Films at High Temperature due to Film Thickness and Substrate

抄録

Rciprocal space maps of CeO₂/YSZ/Si(001) grown by PLD method were obtained at high temperature by adding a heater to the sample stage. CeO₂ and YSZ thin films were epitaxally grown. By measuring lattice constats at high temperature it is conducted that a-axes of CeO₂ and YSZ thin films parallel to the substrate surface showed smaller thermal coefficients than bulk reference and a-axes perpendicular to the surface showed larger thermal coefficients. And in YSZ films a-axes parallel to the substrate surface showed decreasing with temperature around 200-300^oC due to CeO₂ layer thickness, which thought to be the relaxation of thermal stress by generation of dislocations. When another thin film was dedeposited on CeO₂ layer, lattice change of CeO₂ with increasing temperature also differed from that before depositing the top layer.