Flux Pinning Properties of Ce and La Co-Doped GdBa2Cu3Oy Thin Films Fabricated by Fluorine-Free MOD Method

We have fabricated GdBa
₂
Cu
₃
O
_y
(Gd123) thin films co-doped with Ce and La on LaAlO
₃
single crystal substrates by the FF-MOD (Fluorine-Free Metal Organic Deposition) method and investigated their superconducting properties. As a result, we have successfully introduced effective artificial pinning centers by adding Ce for the first time in this method and achieved the remarkable improvement in critical current densities (
J
_c
) in magnetic fields.
J
_c
increased with the increase in the amount of Ce added, and the magnetic field with the maximum pinning force density also increased.
J
_c
was further improved by adding La due to the improved crystallinity of the superconducting phase. The superconducting film co-doped with Ce 3.0 mol% and La 1.0 mol% achieved the highest
J
_c
of 3.35 MA/cm
²
at 0 T and 0.328 MA/cm
²
at 1.0 T under 77.3 K.