Superconducting Properties of BaHfO₃-doped Nd_1+xBa_2-xCu₃O_y Films Prepared by Alternating-targets Technique

In order to clarify the influence of RE/Ba substitution on superconducting properties on REBCO films in magnetic fields, we fabricated BHO-doped Nd_1+xBa_2-xCu₃O_y films in which Nd composition were controlled by PLD method using alternating-targets technique. The T_c of NdBCO(x = 0.01, 0.08) films were about 92 K. For the field applied parallel to the c-axis, a J_c and a characteristic magnetic field of the maximum pinning force of the NdBCO(x = 0.08) film increased compared with those of the NdBCO(x = 0.01) film. Additionally, a J_c of a BHO-doped NdBCO(x = 0.08) film improved for all applied angles of magnetic field in 1 T. The forms of J_c-θ curves for the BHO-NdBCO films with x = 0.01 and 0.08 were similar form. Therefore, it is considered that the reason of J_c increase in the BHO-doped NdBCO(x = 0.08) film is introduction of three-dimensional pinning centers of fine Nd/Ba solid solutions and the solid solution do not influence on the BHO growth.