Superconducting properties in magnetic field of (Nd, Eu, Gd) 1+xBa 2−xCu 3O y thin films prepared by low temperature growth technique

Abstract

In order to achieve high irreversibility field ( B irr), we fabricated (Nd, Eu, Gd)Ba 2Cu 3O y (NEGBCO) thin films by pulsed laser deposition (PLD) method and low temperature growth (LTG) technique. In the LTG–NEGBCO films on MgO, critical current density ( J c) at 77 K and magnetic field B = 5 T was 0.13 MA/cm 2 twice as high as that of PLD–NEGBCO/MgO and B irr at 77 K reached 11.8 T. Interestingly, the anomalous peaks on the J c– B and F p– B (flux pinning force density F p = J c × B) curves at 77 K and B = 4 T were observed on the LTG–NEGBCO/MgO films. From these results, we can consider that NEGBCO films are good candidates and LTG is an effective technique for improving superconducting properties.