Effects of Zr Addition on the Superconducting Properties and Microstructure of MOD-GdBa2Cu3Oy Films Fabricated Using Fluorine-free Coating Solutions

We have fabricated undoped and Zr-doped GdBa2Cu3Oy (GdBCO) films on LaAlO3 single-crystal substrates by metal-organic deposition (MOD) using 2-ethylhexanate (2-EH) solutions, which contain no fluorine. Zr-doped GdBCO films showed improved Jc-B properties compared to the pure films. The Jc and α values of 1-mol%-Zr-doped GdBCO films were 1.58 MA/cm2 and 0.53, respectively, while those of the pure films were 1.90 MA/cm2 and 0.68, respectively.