Effect of annealing atmosphere on the epitaxial growth process of La ₂Zr ₂O ₇ films on different substrates

We have studied the effect of annealing atmosphere on the epitaxial growth process of La ₂Zr ₂O ₇ (LZO) thin films on different substrates fabricated by metal-organic deposition (MOD) method. The structure, texture and morphology of LZO films were investigated by X-ray diffraction (XRD) and atomic force microscopy (AFM). Our results show that the epitaxial growth process of LZO thin film does not completely depend on the lattice mismatch degree between LZO and substrate, and it may be related to the oxygen vacancy defects and the lattice ordering degree. Moreover, the decrease of the lattice oxygen vacancy defects may be beneficial to suppressing the stress and strain relaxation within epitaxial film. The grain boundary concentration in epitaxial films is also related to their strain relaxation process. These results are significant not only to improving the performance of coated conductors, but also to developing other epitaxial oxide thin film on textured substrate.