Enhancement of critical current densities by co-doping with Zr, Sn and Ce for Gd123 thin films fabricated by fluorine-free MOD method

Abstract

Abstract We have fabricated GdBa2Cu3O7-δ thin films co-doped several types of BaMO3 (M=Zr, Sn, Ce) artificial pinning centers with different lattice constants and Young’s modulus from 2.0 to 5.0 mol% on LaAlO3 single crystal substrates by the FF-MOD method. When several types of BaMO3 are simultaneously introduced into Gd123 films by the FF-MOD method, Ba required for BaMO3 crystal growth is shared among them, each crystal growth is suppressed, and thus the crystals become finer and denser. This resulted in a remarkable enhancement of the critical current densities in magnetic fields. The maximum J c of 16.57 MA cm-2 at 0 T and 1.97 MA cm-2 at 3.0 T, 30 K obtained for the Gd123 film introduced three types of BaMO3 (M=Zr, Sn, Ce) with 4.0 mol% were 1.22 and 1.76 times larger than those for the film with the same amount of BaCeO3. This method shows a new strategy to improve Jc in magnetic fields of REBCO.