The superconductivity and pinning properties of Y2O3-doped GdBa2Cu3O7-δ films prepared by pulsed laser deposition

Abstract

We have investigated the effect of Y2O3 nanoparticles on the pinning properties of Y2O3-doped GdBa2Cu3O7-delta (GdBCO) films. Both undoped and Y2O3-doped GdBCO films were grown on CeO2-buffered MgO (100) single crystal substrates by pulsed laser deposition (PLD) using KrF (lambda=248 nm) laser. The Y2O3 doping contents were controlled up to similar to 2.5 area% by varying the internal angles of Y2O3 sectors put on the top surface of GdBCO target. Compared with the Gd2O3-doped GdBCO films previously reported by our group [1], the Y2O3-doped GdBCO films exhibited less severe critical temperature (T-c) drop and thus slightly enhanced critical current densities (J(c)) and pinning force densities (F-p) at 65 K for the applied field parallel to the c-axis of the GdBCO matrix (B//c) with increasing the doping content. Below 40 K, the in-field J(c) and F-p values of all Y2O3-doped GdBCO films exhibited higher than those of undoped GdBCO film, suggesting that Y2O3 inclusions might act as effective pinning centers.