Flux pinning properties in BaMO₃ (M=Zr,Sn) nanorod-introduced ErBa₂ Cu₃ O_x films

Flux pinning properties on the ErBa₂ Ca₃ O ₇ films with the nanoscaled and columnar-shaped BaMO₃ (BMO,M=Zr,Sn) precipitates, i.e., nanorods, were investigated systematically based on the microstructure, critical current density J_c and irreversibility field B_i properties in high magnetic fields. We found that the in-field J_c and B_i increase monotonically with increasing the nanorod density until 3.5 wt % BZO and 6 wt % BSO additions, respectively, although the critical temperature T_c is reduced. According to the flux pinning analysis assuming of the linear summation, the BSO doped samples have the higher performance of the flux pinning than the BZO doped samples quantitatively even after the reduction in the T_c and size of the nanorods. It is considered that those differences originate from the effective pinning length of the nanorods and/or the condensation energy due to the difference of the carrier density.