Influence of Gd/Ba Composition on Superconducting Properties of BaHfO3 doped Gd1+xBa2-xCu3Oy films

In order to investigate an influence of Gd/Ba substitution x in Gd1+xBa2-xCu3Oy (GdBCO) on superconducting properties and microstructures of BaHfO3 (BHO) in GdBCO films, we fabricated the films on IBAD-MgO substrate by pulsed laser deposition (PLD) method. As a result, the number density of BHO nanorods were decreased from 2000 to 1100/μm2 with increasing x up to x = 0.07. If x > 0.07, the density of BaHfO3 nanorods were almost the same with 2000/μm2. Tcs of the BaHfO3 doped films were improved from 88.0 to 90.6 K with increasing x. In addition, the films with x from 0.07 to 0.12 showed high pinning force density Fp, especially the x = 0.10 films shows high Fp = 23.0 GN/m3 at 77 K in B//c.