Growth temperature dependence of flux pinning properties in ErBa ₂Cu₃O_y thin films with nano-rods

Irreversibility lines and distributions of local critical current density (J_cl) based on the percolation transition model were affected by the growth temperature (T_s) in 3.5 wt.%-BaNb₂O ₆-doped ErBa₂Cu₃O_y thin films. The vortex-Bose-glass-like state appeared by the introduction of nano-rods, and this vortex state was affected by T_s. The shape and width of the J _cl distribution strongly depended on T_s. These results are probably caused by variations of the density and the growth direction for nano-rods reflecting T_s. The growth temperature is an important factor to achieve higher critical current properties under magnetic fields for coated conductors of rare-earth-based cuprates with nano-rods.