Microstructural study of EuBa₂Cu₃O₇ films by high resolution X-ray diffraction

Recent studies have shown that EuBa₂Cu₃O₇ (Eu123) films exhibit excellent surface morphology, high transition temperature, and interesting field-dependent critical current density, which are important for thin film devices and coated conductor applications. In this paper, we report our detailed studies of the microstructures of the Eu123 films deposited under different conditions. We have used high-resolution x-ray diffraction (HRXRD) to investigate the texture evolution and micro-domains of the films. Reciprocal space maps (RSMs) show that the a-axis growth of Eu123 films on SrTiO₃ substrates at a given deposition temperature is directly related to the deposition rate. On the other hand, by inserting a DyBa ₂Cu₃O₇ (Dy123) seed layer, the a-axis growth can be totally eliminated. HRXRD study further reveals that micro-domains with different c-axis lattice parameters are often formed in the Eu123/Dy123, which may result from different oxygen content.