Superconducting properties of Sm0.33Eu0.33Gd0.33Ba2Cu3Oy films by metal-organic deposition using metal 2-ethylhexanates

We have prepared Sm0.33Eu0.33Gd0.33Ba2Cu3Oy (SEGBCO) films on LaAlO3 single-crystal substrates by metal-organic deposition using 2-ethylhexanate solutions which contain no fluorine. The SEGBCO film fired at 850 °C under a low oxygen partial pressure of 2 × 10−6 atm exhibited strong c-axis oriented X-ray diffraction peaks and weak a/b-axis oriented peaks of the SEGBCO phase, and had a granular surface. High resolution cross-sectional transmission electron microscope images indicated the epitaxial growth of the SEGBCO film on the substrate with overgrowth of a/b-axis oriented grains. The critical temperature and critical current density values of the SEGBCO film was 86.5 K and 1.29 MA/cm2, respectively, at 77.3 K at the self-field.