Characteristics in the Growth of the YBa₂Cu₃O_x and YBaSrCu₃O_x Crystalline Films

Abstract

The change of the structure of the sputter-deposited amorphous films of YBa₂Cu₃O_x and YBaSrCu₃O_x by the thermal annealing was investigated using the SEM and the X-ray diffraction spectrometry. The YBa₂Cu₃O_x films crystallized in the distorted perovskite structure when annealed above 920°C while the YBaSrCu₃O_x above 980°c The merging of (200), (020) and (006) lines was observed in the YBa₂Cu₃O_x annealed at 800°C or in the YBaSrCu₃O_x annealed between 800°C and 940°C. The existence of the antistructure defects between Y and Ba (Sr) was pointed out in these films. It was also found that by the annealing of the films of YBaSrCu₃O_x , the YBa₂Cu₃O_x crystals grew preferentially below 900C while the YBaSrCu₃O_x crystals grew above 900°C.